XML Example Application: FunDS

	XML Example Application: FunDS (Fun Department Store)

Introduction

XML provide effective and wonderful means to create a database repository. XML by itself doesn't create or save records. It only defines how datashould be stored. On the other hand, another language, a library, or a programming environment can be used to create, save, or maintain data (for example, editing or deleting records).

We are going to create an example database application for a department store. We will name the business as FunDS, which stands for Fun Department Store.

The Employees

Naturally, we need people who can run the business.

Practical Learning: Introducing the Application

Start a text editor such as Notepad and type the following:

using System;
using System.Drawing;
using System.Windows.Forms;

public class EmployeeNew : Form
{
    private Label lblEmployeeNumber;
    public TextBox txtEmployeeNumber;
    private Label lblFirstName;
    public TextBox txtFirstName;
    private Label lblLastName;
    public TextBox txtLastName;
    private Label lblAddress;
    public TextBox txtAddress;
    private Label lblCity;
    public TextBox txtCity;
    private Label lblCounty;
    public TextBox txtCounty;
    private Label lblState;
    public TextBox txtState;
    private Label lblZIPCode;
    public TextBox txtZIPCode;
    private Label lblMaritalStatus;
    public ComboBox cbxMaritalsStatus;
    private Label lblExemptions;
    public TextBox txtExemptions;
    private Label lblHourlySalary;
    public TextBox txtHourlySalary;
    private Button btnOK;
    private Button btnCancel;

    public EmployeeNew()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Employee Number
        lblEmployeeNumber = new Label();
        lblEmployeeNumber.AutoSize = true;
        lblEmployeeNumber.Location = new System.Drawing.Point(13, 18);
        lblEmployeeNumber.TabIndex = 0;
        lblEmployeeNumber.Text = "Employee #:";
        Controls.Add(lblEmployeeNumber);

        // Text Box: Employee Number
        txtEmployeeNumber = new TextBox();
        txtEmployeeNumber.Location = new System.Drawing.Point(94, 16);
        txtEmployeeNumber.Size = new System.Drawing.Size(88, 20);
        txtEmployeeNumber.TabIndex = 1;
        Controls.Add(txtEmployeeNumber);

        // Label: First Name
        lblFirstName = new Label();
        lblFirstName.AutoSize = true;
        lblFirstName.Location = new System.Drawing.Point(13, 49);
        lblFirstName.TabIndex = 2;
        lblFirstName.Text = "First Name:";
        Controls.Add(lblFirstName);

        // Text Box: First Name
        txtFirstName = new TextBox();
        txtFirstName.Location = new System.Drawing.Point(94, 46);
        txtFirstName.Size = new System.Drawing.Size(88, 20);
        txtFirstName.TabIndex = 3;
        Controls.Add(txtFirstName);

        // Label: Last Name
        lblLastName = new Label();
        lblLastName.AutoSize = true;
        lblLastName.Location = new System.Drawing.Point(195, 49);
        lblLastName.TabIndex = 4;
        lblLastName.Text = "Last Name:";
        Controls.Add(lblLastName);

        // Text Box: Last Name
        txtLastName = new TextBox();
        txtLastName.Location = new System.Drawing.Point(276, 46);
        txtLastName.Size = new System.Drawing.Size(88, 20);
        txtLastName.TabIndex = 5;
        Controls.Add(txtLastName);

        // Label: Address
        lblAddress = new Label();
        lblAddress.AutoSize = true;
        lblAddress.Location = new System.Drawing.Point(13, 75);
        lblAddress.TabIndex = 6;
        lblAddress.Text = "Address:";
        Controls.Add(lblAddress);

        // Text Box: Address
        txtAddress = new TextBox();
        txtAddress.Location = new System.Drawing.Point(94, 72);
        txtAddress.Size = new System.Drawing.Size(270, 20);
        txtAddress.TabIndex = 7;
        Controls.Add(txtAddress);

        // Label: City
        lblCity = new Label();
        lblCity.AutoSize = true;
        lblCity.Location = new System.Drawing.Point(13, 101);
        lblCity.TabIndex = 8;
        lblCity.Text = "City:";
        Controls.Add(lblCity);

        // Text Box: City
        txtCity = new TextBox();
        txtCity.Location = new System.Drawing.Point(94, 98);
        txtCity.Size = new System.Drawing.Size(270, 20);
        txtCity.TabIndex = 9;
        Controls.Add(txtCity);

        // Label: County
        lblCounty = new Label();
        lblCounty.AutoSize = true;
        lblCounty.Location = new System.Drawing.Point(13, 127);
        lblCounty.TabIndex = 10;
        lblCounty.Text = "County:";
        Controls.Add(lblCounty);

        // Text Box: County
        txtCounty = new TextBox();
        txtCounty.Location = new System.Drawing.Point(94, 124);
        txtCounty.Size = new System.Drawing.Size(88, 20);
        txtCounty.TabIndex = 11;
        Controls.Add(txtCounty);

        // Label: State
        lblState = new Label();
        lblState.AutoSize = true;
        lblState.Location = new System.Drawing.Point(195, 127);
        lblState.TabIndex = 12;
        lblState.Text = "State:";
        Controls.Add(lblState);

        // Text Box: State
        txtState = new TextBox();
        txtState.Location = new System.Drawing.Point(276, 124);
        txtState.Size = new System.Drawing.Size(88, 20);
        txtState.TabIndex = 13;
        Controls.Add(txtState);
       
        // Label: ZIP Code
        lblZIPCode = new Label();
        lblZIPCode.AutoSize = true;
        lblZIPCode.Location = new System.Drawing.Point(13, 153);
        lblZIPCode.TabIndex = 14;
        lblZIPCode.Text = "ZIP Code:";
        Controls.Add(lblZIPCode);

        // Text Box: ZIP Code
        txtZIPCode = new TextBox();
        txtZIPCode.Location = new System.Drawing.Point(94, 150);
        txtZIPCode.Size = new System.Drawing.Size(88, 20);
        txtZIPCode.TabIndex = 15;
        Controls.Add(txtZIPCode);

        // Label: Marital Status
        lblMaritalStatus = new Label();
        lblMaritalStatus.AutoSize = true;
        lblMaritalStatus.Location = new System.Drawing.Point(195, 153);
        lblMaritalStatus.TabIndex = 16;
        lblMaritalStatus.Text = "Marital Status:";
        Controls.Add(lblMaritalStatus);

        // Combo Box: Maritals Status
        cbxMaritalsStatus = new ComboBox();
        cbxMaritalsStatus.Items.AddRange(new object[] { "Single", "Married"});
        cbxMaritalsStatus.Location = new System.Drawing.Point(276, 150);
        cbxMaritalsStatus.Size = new System.Drawing.Size(88, 21);
        cbxMaritalsStatus.TabIndex = 17;
        Controls.Add(cbxMaritalsStatus);

        // Label: Exemptions
        lblExemptions = new Label();
        lblExemptions.AutoSize = true;
        lblExemptions.Location = new System.Drawing.Point(13, 179);
        lblExemptions.TabIndex = 18;
        lblExemptions.Text = "Exemptions:";
        Controls.Add(lblExemptions);

        // Text Box: Exemptions
        txtExemptions = new TextBox();
        txtExemptions.Location = new System.Drawing.Point(94, 176);
        txtExemptions.Size = new System.Drawing.Size(88, 20);
        txtExemptions.TabIndex = 19;
        txtExemptions.Text = "0";
        txtExemptions.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtExemptions);

        // Label: Hourly Salary
        lblHourlySalary = new Label();
        lblHourlySalary.AutoSize = true;
        lblHourlySalary.Location = new System.Drawing.Point(195, 180);
        lblHourlySalary.TabIndex = 20;
        lblHourlySalary.Text = "Hourly Salary:";
        Controls.Add(lblHourlySalary);
        
        // Text Box: Hourly Salary
        txtHourlySalary = new TextBox();
        txtHourlySalary.Location = new System.Drawing.Point(276, 177);
        txtHourlySalary.Size = new System.Drawing.Size(88, 20);
        txtHourlySalary.TabIndex = 21;
        Controls.Add(txtHourlySalary);

        // Button: OK
        btnOK = new Button();
        btnOK.DialogResult = DialogResult.OK;
        btnOK.Location = new System.Drawing.Point(202, 220);
        btnOK.Size = new System.Drawing.Size(75, 23);
        btnOK.TabIndex = 22;
        btnOK.Text = "OK";
        Controls.Add(btnOK);

        // Button: Cancel
        btnCancel = new Button();
        btnCancel.DialogResult = DialogResult.Cancel;
        btnCancel.Location = new System.Drawing.Point(288, 220);
        btnCancel.Size = new System.Drawing.Size(75, 23);
        btnCancel.TabIndex = 23;
        btnCancel.Text = "Cancel";
        Controls.Add(btnCancel);

        // Form: New Employee
        AcceptButton = this.btnOK;
        CancelButton = this.btnCancel;
        ClientSize = new System.Drawing.Size(388, 260);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "Fun Department Store - New Employee";
    }
}

To save and start a new file, on the main menu, click File -> New
When asked whether you want to save, click Save
In the top combo box, select and display the C: drive
Click the New Folder button
Type FunDS1 and press Enter twice to display it in the top combo box
Change the Save As Type combo box to All Files
Set the File Name to EmployeeNew.cs
Click Save

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class EmployeeEditor : Form
{
    private Label lblEmployeeNumber;
    public TextBox txtEmployeeNumber;
    private Button btnFind;
    private Label lblFirstName;
    public TextBox txtFirstName;
    private Label lblLastName;
    public TextBox txtLastName;
    private Label lblAddress;
    public TextBox txtAddress;
    private Label lblCity;
    public TextBox txtCity;
    private Label lblCounty;
    public TextBox txtCounty;
    private Label lblState;
    public TextBox txtState;
    private Label lblZIPCode;
    public TextBox txtZIPCode;
    private Label lblMaritalStatus;
    public ComboBox cbxMaritalsStatus;
    private Label lblExemptions;
    public TextBox txtExemptions;
    private Label lblHourlySalary;
    public TextBox txtHourlySalary;
    private Button btnSubmit;
    private Button btnClose;

    public EmployeeEditor()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Employee Number
        lblEmployeeNumber = new Label();
        lblEmployeeNumber.AutoSize = true;
        lblEmployeeNumber.Location = new System.Drawing.Point(13, 18);
        lblEmployeeNumber.TabIndex = 0;
        lblEmployeeNumber.Text = "Employee #:";
        Controls.Add(lblEmployeeNumber);

        // Text Box: Employee Number
        txtEmployeeNumber = new TextBox();
        txtEmployeeNumber.Location = new System.Drawing.Point(94, 16);
        txtEmployeeNumber.Size = new System.Drawing.Size(88, 20);
        txtEmployeeNumber.TabIndex = 1;
        Controls.Add(txtEmployeeNumber);

        // Button: Find
        btnFind = new Button();
        btnFind.Location = new System.Drawing.Point(201, 18);
        btnFind.Size = new System.Drawing.Size(75, 23);
        btnFind.TabIndex = 2;
        btnFind.Text = "Find";
        btnFind.Click += new System.EventHandler(btnFindClick);
        Controls.Add(btnFind);

        // Label: First Name
        lblFirstName = new Label();
        lblFirstName.AutoSize = true;
        lblFirstName.Location = new System.Drawing.Point(13, 49);
        lblFirstName.TabIndex = 5;
        lblFirstName.Text = "First Name:";
        Controls.Add(lblFirstName);

        // Text Box: First Name
        txtFirstName = new TextBox();
        txtFirstName.Location = new System.Drawing.Point(94, 46);
        txtFirstName.Size = new System.Drawing.Size(88, 20);
        txtFirstName.TabIndex = 6;
        Controls.Add(txtFirstName);

        // Label: Last Name
        lblLastName = new Label();
        lblLastName.AutoSize = true;
        lblLastName.Location = new System.Drawing.Point(195, 49);
        lblLastName.TabIndex = 7;
        lblLastName.Text = "Last Name:";
        Controls.Add(lblLastName);

        // Text Box: Last Name
        txtLastName = new TextBox();
        txtLastName.Location = new System.Drawing.Point(276, 46);
        txtLastName.Size = new System.Drawing.Size(88, 20);
        txtLastName.TabIndex = 8;
        Controls.Add(txtLastName);

        // Label: Address
        lblAddress = new Label();
        lblAddress.AutoSize = true;
        lblAddress.Location = new System.Drawing.Point(13, 75);
        lblAddress.TabIndex = 9;
        lblAddress.Text = "Address:";
        Controls.Add(lblAddress);

        // Text Box: Address
        txtAddress = new TextBox();
        txtAddress.Location = new System.Drawing.Point(94, 72);
        txtAddress.Size = new System.Drawing.Size(270, 20);
        txtAddress.TabIndex = 10;
        Controls.Add(txtAddress);

        // Label: City
        lblCity = new Label();
        lblCity.AutoSize = true;
        lblCity.Location = new System.Drawing.Point(13, 101);
        lblCity.TabIndex = 11;
        lblCity.Text = "City:";
        Controls.Add(lblCity);

        // Text Box: City
        txtCity = new TextBox();
        txtCity.Location = new System.Drawing.Point(94, 98);
        txtCity.Size = new System.Drawing.Size(270, 20);
        txtCity.TabIndex = 12;
        Controls.Add(txtCity);

        // Label: County
        lblCounty = new Label();
        lblCounty.AutoSize = true;
        lblCounty.Location = new System.Drawing.Point(13, 127);
        lblCounty.TabIndex = 13;
        lblCounty.Text = "County:";
        Controls.Add(lblCounty);

        // Text Box: County
        txtCounty = new TextBox();
        txtCounty.Location = new System.Drawing.Point(94, 124);
        txtCounty.Size = new System.Drawing.Size(88, 20);
        txtCounty.TabIndex = 14;
        Controls.Add(txtCounty);

        // Label: State
        lblState = new Label();
        lblState.AutoSize = true;
        lblState.Location = new System.Drawing.Point(195, 127);
        lblState.TabIndex = 15;
        lblState.Text = "State:";
        Controls.Add(lblState);

        // Text Box: State
        txtState = new TextBox();
        txtState.Location = new System.Drawing.Point(276, 124);
        txtState.Size = new System.Drawing.Size(88, 20);
        txtState.TabIndex = 16;
        Controls.Add(txtState);

        // Label: ZIP Code
        lblZIPCode = new Label();
        lblZIPCode.AutoSize = true;
        lblZIPCode.Location = new System.Drawing.Point(13, 153);
        lblZIPCode.TabIndex = 17;
        lblZIPCode.Text = "ZIP Code:";
        Controls.Add(lblZIPCode);

        // Text Box: ZIP Code
        txtZIPCode = new TextBox();
        txtZIPCode.Location = new System.Drawing.Point(94, 150);
        txtZIPCode.Size = new System.Drawing.Size(88, 20);
        txtZIPCode.TabIndex = 18;
        Controls.Add(txtZIPCode);

        // Label: Marital Status
        lblMaritalStatus = new Label();
        lblMaritalStatus.AutoSize = true;
        lblMaritalStatus.Location = new System.Drawing.Point(195, 153);
        lblMaritalStatus.TabIndex = 19;
        lblMaritalStatus.Text = "Marital Status:";
        Controls.Add(lblMaritalStatus);
        
        // Combo Box: MaritalsStatus
        cbxMaritalsStatus = new ComboBox();
        cbxMaritalsStatus.Items.AddRange(new object[] { "Single", "Married"});
        cbxMaritalsStatus.Location = new System.Drawing.Point(276, 150);
        cbxMaritalsStatus.Size = new System.Drawing.Size(88, 21);
        cbxMaritalsStatus.TabIndex = 20;
        Controls.Add(cbxMaritalsStatus);

        // Label: Exemptions
        lblExemptions = new Label();
        lblExemptions.AutoSize = true;
        lblExemptions.Location = new System.Drawing.Point(13, 179);
        lblExemptions.TabIndex = 21;
        lblExemptions.Text = "Exemptions:";
        Controls.Add(lblExemptions);

        // Text Box: Exemptions
        txtExemptions = new TextBox();
        txtExemptions.Location = new System.Drawing.Point(94, 176);
        txtExemptions.Size = new System.Drawing.Size(88, 20);
        txtExemptions.TabIndex = 22;
        txtExemptions.Text = "0";
        txtExemptions.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtExemptions);

        // Label: Hourly Salary
        lblHourlySalary = new Label();
        lblHourlySalary.AutoSize = true;
        lblHourlySalary.Location = new System.Drawing.Point(195, 180);
        lblHourlySalary.TabIndex = 23;
        lblHourlySalary.Text = "Hourly Salary:";
        Controls.Add(lblHourlySalary);

        // Text Box: Hourly Salary
        txtHourlySalary = new TextBox();
        txtHourlySalary.Location = new System.Drawing.Point(276, 177);
        txtHourlySalary.Size = new System.Drawing.Size(88, 20);
        txtHourlySalary.TabIndex = 24;
        Controls.Add(txtHourlySalary);

        // Button: Submit
        btnSubmit = new Button();
        btnSubmit.Location = new System.Drawing.Point(207, 218);
        btnSubmit.Size = new System.Drawing.Size(84, 23);
        btnSubmit.TabIndex = 3;
        btnSubmit.Text = "Submit";
        btnSubmit.Click += new System.EventHandler(btnSubmitClick);
        Controls.Add(btnSubmit);

        // Button: Close
        btnClose = new Button();
        btnClose.Location = new System.Drawing.Point(297, 218);
        btnClose.Size = new System.Drawing.Size(75, 23);
        btnClose.TabIndex = 4;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);
        Controls.Add(btnClose);
            
        // Form: Employee Editor
        ClientSize = new System.Drawing.Size(394, 259);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "Fun Department Store: Employee Editor";
    }

    private void btnFindClick(object sender, EventArgs e)
    {
        bool employeeFound = false;
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        if (string.IsNullOrEmpty(txtEmployeeNumber.Text))
        {
            MessageBox.Show("You must enter an employee number.", "FunDS - Employees Records", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }

        if (File.Exists(strEmployeesFile))
        {
            using (FileStream fsEmployees = new FileStream(strEmployeesFile, FileMode.Open, FileAccess.Read))
            {
                xdEmployees.Load(fsEmployees);

                XmlNodeList xnlEmployees = xdEmployees.GetElementsByTagName("EmployeeNumber");

                foreach (XmlNode xnEmployee in xnlEmployees)
                {
                    if (xnEmployee.InnerText == txtEmployeeNumber.Text)
                    {
                        txtFirstName.Text = xnEmployee.NextSibling.InnerText; // First Name
                        txtLastName.Text = xnEmployee.NextSibling.NextSibling.InnerText; // Last Name
                        txtAddress.Text = xnEmployee.NextSibling.NextSibling.NextSibling.InnerText; // Address
                        txtCity.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // City
                        txtCounty.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // County
                        txtState.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // State
                        txtZIPCode.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // ZIP Code
                        cbxMaritalsStatus.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // Marital Status
                        txtExemptions.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // Exemptions
                        txtHourlySalary.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // Hourly Salary

                        employeeFound = true;
                    }
                }

                if (employeeFound == false)
                {
                    MessageBox.Show("There is no staff member with that employee number.", "FunDS - Employees Records", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    return;
                }
            }
        }
    }

    private void btnSubmitClick(object sender, EventArgs e)
    {
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        if (string.IsNullOrEmpty(txtEmployeeNumber.Text))
        {
            MessageBox.Show("You must enter an employee number.",
                            "FunDS - Employees Records",
                            MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }

        if (File.Exists(strEmployeesFile))
        {
            using (FileStream fsEmployees = new FileStream(strEmployeesFile, FileMode.Open, FileAccess.Read))
            {
                xdEmployees.Load(fsEmployees);

                XmlNodeList xnlEmployees = xdEmployees.GetElementsByTagName("EmployeeNumber");

                foreach (XmlNode xnEmployee in xnlEmployees)
                {
                    if (xnEmployee.InnerText == txtEmployeeNumber.Text)
                    {
                        xnEmployee.ParentNode.InnerXml = "<EmployeeNumber>" + txtEmployeeNumber.Text + "</EmployeeNumber>" +
                                                         "<FirstName>" + txtFirstName.Text + "</FirstName>" +
                                                         "<LastName>" + txtLastName.Text + "</LastName>" +
                                                         "<Address>" + txtAddress.Text + "</Address>" +
                                                         "<City>" + txtCity.Text + "</City>" +
                                                         "<County>" + txtCounty.Text + "</County>" +
                                                         "<State>" + txtState.Text + "</State>" +
                                                         "<ZIPCode>" + txtZIPCode.Text + "</ZIPCode>" +
                                                         "<MaritalStatus>" + cbxMaritalsStatus.Text + "</MaritalStatus>" +
                                                         "<Exemptions>" + txtExemptions.Text + "</Exemptions>" +
                                                         "<HourlySalary>" + txtHourlySalary.Text + "</HourlySalary>";
                        break;
                    }
                }
            }

            using (FileStream fsEmployees = new FileStream(strEmployeesFile, FileMode.Create, FileAccess.Write))
            {
                xdEmployees.Save(fsEmployees);

                MessageBox.Show("The employee's record has been updated.",
                                "FunDS - Employees Records",
                                MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }

        Close();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }
}

To save and start a new filew, on the main menu, click File -> New
When asked whether you want to save, click Save
Make sure the FunDS1 folder is displaying in the top combo box. Set the Save As Type combo box to All Files
Set the File Name to EmployeeEditor.cs
Click Save

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class Employees : Form
{
    private ColumnHeader colEmployeeNumber;
    private ColumnHeader colFirstName;
    private ColumnHeader colLastName;
    private ColumnHeader colAddress;
    private ColumnHeader colCity;
    private ColumnHeader colCounty;
    private ColumnHeader colState;
    private ColumnHeader colZIPCode;
    private ColumnHeader colMaritalStatus;
    private ColumnHeader colExemptions;
    private ColumnHeader colHourlySalary;
    private ListView lvwEmployees;

    private Label lblNumberOfEmployees;
    private TextBox txtNumberOfEmployees;
    private Button btnNewEmployee;
    private Button btnClose;

    public Employees()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Column: Employee Number
        colEmployeeNumber = new ColumnHeader();
        colEmployeeNumber.Text = "Employee #";
        colEmployeeNumber.Width = 70;

        // Column: First Name
        colFirstName = new ColumnHeader();
        colFirstName.Text = "First Name";
        colFirstName.Width = 65;

        // Column: Last Name
        colLastName = new ColumnHeader();
        colLastName.Text = "Last Name";
        colLastName.Width = 70;

        // Column: Address
        colAddress = new ColumnHeader();
        colAddress.Text = "Address";
        colAddress.Width = 125;

        // Column: City
        colCity = new ColumnHeader();
        colCity.Text = "City";
        colCity.Width = 75;

        // Column: Username
        colCounty = new ColumnHeader();
        colCounty.Text = "County";

        // Column: State
        colState = new ColumnHeader();
        colState.Text = "State";
        colState.Width = 40;

        // Column: ZIP Code
        colZIPCode = new ColumnHeader();
        colZIPCode.Text = "ZIP Code";

        // Column: Marital Status
        colMaritalStatus = new ColumnHeader();
        colMaritalStatus.Text = "Marital Status";
        colMaritalStatus.Width = 80;

        // Column: Exemptions
        colExemptions = new ColumnHeader();
        colExemptions.Text = "Exemptions";
        colExemptions.TextAlign = HorizontalAlignment.Right;
        colExemptions.Width = 70;

        // Column: Hourly Salary
        colHourlySalary = new ColumnHeader();
        colHourlySalary.Text = "Salary";
        colHourlySalary.TextAlign = HorizontalAlignment.Right;
        colHourlySalary.Width = 45;

        // List View: Employees
        lvwEmployees = new ListView();
        lvwEmployees.Anchor = AnchorStyles.Top | AnchorStyles.Bottom
                            | AnchorStyles.Left | AnchorStyles.Right;
        lvwEmployees.Columns.AddRange(new ColumnHeader[]
        {
            colEmployeeNumber, colFirstName, colLastName,
            colAddress, colCity, colCounty, colState, colZIPCode, 
            colMaritalStatus, colExemptions, colHourlySalary
        });
        lvwEmployees.FullRowSelect = true;
        lvwEmployees.GridLines = true;
        lvwEmployees.Location = new System.Drawing.Point(16, 12);
        lvwEmployees.Size = new System.Drawing.Size(785, 125);
        lvwEmployees.TabIndex = 25;
        lvwEmployees.View = View.Details;
        lvwEmployees.DoubleClick += new EventHandler(lvwEmployeesDoubleClick);

        // Label: NumberOfEmployees
        lblNumberOfEmployees = new Label();
        lblNumberOfEmployees.Anchor = AnchorStyles.Bottom | AnchorStyles.Left;
        lblNumberOfEmployees.AutoSize = true;
        lblNumberOfEmployees.Location = new Point(12, 158);
        lblNumberOfEmployees.Size = new System.Drawing.Size(113, 13);
        lblNumberOfEmployees.TabIndex = 28;
        lblNumberOfEmployees.Text = "Number of Employees:";

        // Text Box: NumberOfEmployees
        txtNumberOfEmployees = new TextBox();
        txtNumberOfEmployees.Anchor = AnchorStyles.Bottom | AnchorStyles.Left;
        txtNumberOfEmployees.Location = new Point(131, 155);
        txtNumberOfEmployees.Size = new System.Drawing.Size(60, 20);
        txtNumberOfEmployees.TabIndex = 29;
        txtNumberOfEmployees.TextAlign = HorizontalAlignment.Right;

        // Button: NewEmployee
        btnNewEmployee = new Button();
        btnNewEmployee.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
        btnNewEmployee.Location = new Point(564, 153);
        btnNewEmployee.Size = new System.Drawing.Size(109, 23);
        btnNewEmployee.TabIndex = 27;
        btnNewEmployee.Text = "New Employee ...";
        btnNewEmployee.Click += new System.EventHandler(btnNewEmployeeClick);

        // Button: Close
        btnClose = new Button();
        btnClose.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
        btnClose.Location = new Point(679, 153);
        btnClose.Size = new System.Drawing.Size(75, 23);
        btnClose.TabIndex = 26;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);

        // Form: Employees
        ClientSize = new System.Drawing.Size(820, 185);
        Controls.Add(lvwEmployees);
        Controls.Add(txtNumberOfEmployees);
        Controls.Add(lblNumberOfEmployees);
        Controls.Add(btnNewEmployee);
        Controls.Add(btnClose);

        MaximizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - Employees";
        Load += new System.EventHandler(EmployeesLoad);
    }

    private void ShowEmployees()
    {
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        if( File.Exists(strEmployeesFile))
        {
            lvwEmployees.Items.Clear();
            using (FileStream fsEmployees = new FileStream(strEmployeesFile, FileMode.Open, FileAccess.Read))
            {
                xdEmployees.Load(fsEmployees);

                XmlNodeList xnlEmployees = xdEmployees.GetElementsByTagName("EmployeeNumber");

                foreach (XmlNode xnEmployee in xnlEmployees)
                {
                    ListViewItem lviEmployee = new ListViewItem(xnEmployee.InnerText); // Employee Number
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.InnerText); // First Name
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.InnerText); // Last Name
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.InnerText); // Address
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // City
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // County
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // State
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // ZIP Code
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // Marital Status
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // Exemptions
                    lviEmployee.SubItems.Add(xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // Hourly Salary

                    lvwEmployees.Items.Add(lviEmployee);
                }

                txtNumberOfEmployees.Text = xnlEmployees.Count.ToString();
            }
        }
    }

    private void EmployeesLoad(object sender, EventArgs e)
    {
        ShowEmployees();
    }

    private void btnNewEmployeeClick(object sender, EventArgs e)
    {
        string strEmployeeNumber, strFirstName, strLastName, strCounty,
               strAddress, strCity, strState, strZIPCode, strMaritalStatus;
        int iExemptions;
        double dblHourlySalary;

        EmployeeNew en = new EmployeeNew();
        Random rndEmployeeNumber = new Random();
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        en.txtEmployeeNumber.Text = rndEmployeeNumber.Next(100000, 999999).ToString();

        if (en.ShowDialog() == DialogResult.OK)
        {
            strEmployeeNumber = en.txtEmployeeNumber.Text;
            strFirstName = en.txtFirstName.Text;
            strLastName = en.txtLastName.Text;
            strMaritalStatus = en.cbxMaritalsStatus.Text;
            iExemptions = int.Parse(en.txtExemptions.Text);
            strAddress = en.txtAddress.Text;
            strCity = en.txtCity.Text;
            strCounty = en.txtCounty.Text;
            strState = en.txtState.Text;
            strZIPCode = en.txtZIPCode.Text;
            dblHourlySalary = double.Parse(en.txtHourlySalary.Text);

            if (!File.Exists(strEmployeesFile))
            {
                xdEmployees.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                                    "<Employees></Employees>");
                xdEmployees.Save(strEmployeesFile);
            }

            xdEmployees.Load(strEmployeesFile);

            XmlElement elmXML = xdEmployees.CreateElement("Employee");
            // Create the XML code of the child element of Employee
            string strNewEmployee = "<EmployeeNumber>" + strEmployeeNumber + "</EmployeeNumber>" +
                                    "<FirstName>" + strFirstName + "</FirstName>" +
                                    "<LastName>" + strLastName + "</LastName>" +
                                    "<Address>" + strAddress + "</Address>" +
                                    "<City>" + strCity + "</City>" +
                                    "<County>" + strCounty + "</County>" +
                                    "<State>" + strState + "</State>" +
                                    "<ZIPCode>" + strZIPCode + "</ZIPCode>" +
                                    "<MaritalStatus>" + strMaritalStatus + "</MaritalStatus>" +
                                    "<Exemptions>" + iExemptions + "</Exemptions>" +
                                    "<HourlySalary>" + dblHourlySalary + "</HourlySalary>";
            elmXML.InnerXml = strNewEmployee;
            // Append the new element as a child of employees
            xdEmployees.DocumentElement.AppendChild(elmXML);

            // Save the XML file
            xdEmployees.Save(strEmployeesFile);

            ShowEmployees();
        }
    }

    private void lvwEmployeesDoubleClick(object sender, EventArgs e)
    {
        EmployeeEditor ee = new EmployeeEditor();
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        if (lvwEmployees.Items.Count <= 0)
            return;

        using (FileStream fsEmployees = new FileStream(strEmployeesFile, FileMode.Open, FileAccess.Read))
        {
            xdEmployees.Load(fsEmployees);

            XmlNodeList xnlEmployees = xdEmployees.GetElementsByTagName("EmployeeNumber");

            foreach (XmlNode xnEmployee in xnlEmployees)
            {
                if (xnEmployee.InnerText == lvwEmployees.SelectedItems[0].Text)
                {
                    ee.txtEmployeeNumber.Text = xnEmployee.InnerText; // 
                    ee.txtFirstName.Text = xnEmployee.NextSibling.InnerText; // First Name
                    ee.txtLastName.Text = xnEmployee.NextSibling.NextSibling.InnerText; // Last Name
                    ee.txtAddress.Text = xnEmployee.NextSibling.NextSibling.NextSibling.InnerText; // Address
                    ee.txtCity.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // City
                    ee.txtCounty.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // County
                    ee.txtState.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // State
                    ee.txtZIPCode.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // ZIP Code
                    ee.cbxMaritalsStatus.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // Marital Status
                    ee.txtExemptions.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // Exemptions
                    ee.txtHourlySalary.Text = xnEmployee.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText; // Hourly Salary
                }
            }
        }

        ee.ShowDialog();
        ShowEmployees();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }
}

To save, on the main menu, click File -> New

When asked whether you want to save, click Save

Make sure the FunDS1 folder is displaying in the top combo box and change the Save As Type to All Files
Set the File Name to Employees.cs
Click Save

Handling Store Items

Items (such as clothing, jewelry, and accessories, etc) are the basis of the business. For our database, the three most important pieces of information about each item are the item number (which must be unique for each item), a name or short description, and a price. Other pieces of information we will consider for some items are the manufacturer, the category, and the subcategory. We will also apply a discount rate to some items.

Practical Learning: Creating Store Items

In the empty document, type the following:

using System;
using System.Drawing;
using System.Windows.Forms;

public class Manufacturer : Form
{
    private Label lblManufacturer;
    public TextBox txtManufacturer;
    private Button btnOK;
    private Button btnCancel;

    public Manufacturer()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Manufacturer
        lblManufacturer = new Label();
        lblManufacturer.AutoSize = true;
        lblManufacturer.Location = new System.Drawing.Point(21, 20);
        lblManufacturer.TabIndex = 0;
        lblManufacturer.Text = "Manufacturer:";
        Controls.Add(lblManufacturer);

        // Text Box: Manufacturer
        txtManufacturer = new TextBox();
        txtManufacturer.Location = new System.Drawing.Point(100, 17);
        txtManufacturer.Size = new System.Drawing.Size(156, 20);
        txtManufacturer.TabIndex = 1;
        Controls.Add(txtManufacturer);

        // Button: OK
        btnOK = new Button();
        btnOK.DialogResult = DialogResult.OK;
        btnOK.Location = new System.Drawing.Point(100, 53);
        btnOK.Size = new System.Drawing.Size(75, 23);
        btnOK.TabIndex = 3;
        btnOK.Text = "OK";
        Controls.Add(btnOK);

        // Button: Cancel
        btnCancel = new Button();
        btnCancel.DialogResult = DialogResult.Cancel;
        btnCancel.Location = new System.Drawing.Point(181, 53);
        btnCancel.Size = new System.Drawing.Size(75, 23);
        btnCancel.TabIndex = 2;
        btnCancel.Text = "Cancel";
        Controls.Add(btnCancel);

        // Dialog Box: Manufacturer
        AcceptButton = this.btnOK;
        CancelButton = this.btnCancel;
        ClientSize = new System.Drawing.Size(276, 92);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        ShowInTaskbar = false;
        Text = "FunDS - Manufacturer";
        StartPosition = FormStartPosition.CenterScreen;
    }
}

To save and start a new file, on the main menu, click File -> New
When asked whether you want save, click Yes (or Save)
In the top combo box, make sure FunDS1 is selected. Set the name to Manufacturer.cs
Change the Save As Type to All Files
Click Save

In the empty document, type the following:

using System;
using System.Drawing;
using System.Windows.Forms;

public class Category : Form
{
    private Button btnOK;
    private Button btnCancel;
    private Label lblCategory;
    public TextBox txtCategory;

    public Category()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Category
        lblCategory = new Label();
        lblCategory.AutoSize = true;
        lblCategory.Location = new System.Drawing.Point(21, 20);
        lblCategory.TabIndex = 4;
        lblCategory.Text = "Category:";
        Controls.Add(lblCategory);

        // Text Box: Category
        txtCategory = new TextBox();
        txtCategory.Location = new System.Drawing.Point(100, 17);
        txtCategory.Size = new System.Drawing.Size(156, 20);
        txtCategory.TabIndex = 5;
        Controls.Add(txtCategory);

        // Button: OK
        btnOK = new Button();
        btnOK.DialogResult = DialogResult.OK;
        btnOK.Location = new System.Drawing.Point(100, 53);
        btnOK.Size = new System.Drawing.Size(75, 23);
        btnOK.TabIndex = 7;
        btnOK.Text = "OK";
        btnOK.UseVisualStyleBackColor = true;
        Controls.Add(btnOK);

        // Button: Cancel
        btnCancel = new Button();
        btnCancel.DialogResult = DialogResult.Cancel;
        btnCancel.Location = new System.Drawing.Point(181, 53);
        btnCancel.Size = new System.Drawing.Size(75, 23);
        btnCancel.TabIndex = 6;
        btnCancel.Text = "Cancel";
        Controls.Add(btnCancel);

        // Dialog Box: Category 
        AcceptButton = this.btnOK;
        CancelButton = this.btnCancel;
        ClientSize = new System.Drawing.Size(276, 93);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        ShowInTaskbar = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - Category";
    }
}

To save and start a new file, on the main menu, click File -> New
When asked whether you want to save, click Save
Make sure FunDS1 is selected in the top combo box and set the File Name to Category.cs
Set the Save As Type combo box to All Files
Click Save

In the empty document, type the following:

using System;
using System.Drawing;
using System.Windows.Forms;

public class SubCategory : Form
{
    private Label lblSubCategory;
    public TextBox txtSubCategory;
    private Button btnOK;
    private Button btnCancel;

    public SubCategory()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        lblSubCategory = new Label();
        lblSubCategory.AutoSize = true;
        lblSubCategory.Location = new System.Drawing.Point(21, 20);
        lblSubCategory.TabIndex = 0;
        lblSubCategory.Text = "Sub-Category:";
        Controls.Add(lblSubCategory);

        txtSubCategory = new TextBox();
        txtSubCategory.Location = new System.Drawing.Point(100, 17);
        txtSubCategory.Size = new System.Drawing.Size(156, 20);
        txtSubCategory.TabIndex = 1;
        Controls.Add(txtSubCategory);

        btnOK = new Button();
        btnOK.DialogResult = DialogResult.OK;
        btnOK.Location = new System.Drawing.Point(100, 53);
        btnOK.Size = new System.Drawing.Size(75, 23);
        btnOK.TabIndex = 2;
        btnOK.Text = "OK";
        Controls.Add(btnOK);

        btnCancel = new Button();
        btnCancel.DialogResult = DialogResult.Cancel;
        btnCancel.Location = new System.Drawing.Point(181, 53);
        btnCancel.Size = new System.Drawing.Size(75, 23);
        btnCancel.TabIndex = 3;
        btnCancel.Text = "Cancel";
        Controls.Add(btnCancel);

        AcceptButton = btnOK;
        CancelButton = btnCancel;
        ClientSize = new System.Drawing.Size(276, 93);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        ShowInTaskbar = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - Category";
    }
}

To save and start a new file, on the main menu, click File -> New
When asked whether you want to save, click Save
In the top combo box, make sure the FunDS1 folder is selected. Set the Save As Type combo box to All Files
Set the File Name to SubCategory.cs
Click Save

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class StoreItemNew : Form
{
    private Label lblItemNumber;
    public TextBox txtItemNumber;
    private Label lblManufacturer;
    public ComboBox cbxManufacturers;
    private Button btnNewManufacturer;
    private Label lblCategory;
    private Label lblSubCategory;
    private Label lblUnitPrice;
    private Label lblDiscountRate;
    private Label lblDiscountPercent;
    private Button btnNewCategory;
    private Button btnNewSubCategory;
    private Button btnSubmit;
    private Button btnClose;
    public ComboBox cbxCategories;
    public ComboBox cbxSubCategories;
    private Label lblItemName;
    public TextBox txtItemName;
    private Label lblItemSize;
    public TextBox txtItemSize;
    public TextBox txtUnitPrice;
    public TextBox txtDiscountRate;
    private Button btnReset;

    public StoreItemNew()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        lblItemNumber = new Label();
        lblItemNumber.AutoSize = true;
        lblItemNumber.Location = new Point(17, 24);
        lblItemNumber.TabIndex = 2;
        lblItemNumber.Text = "Item Number:";
        Controls.Add(lblItemNumber);

        // Label: Item Number
        txtItemNumber = new TextBox();
        txtItemNumber.Location = new Point(96, 21);
        txtItemNumber.Size = new System.Drawing.Size(94, 20);
        txtItemNumber.TabIndex = 3;
        Controls.Add(txtItemNumber);

        // Label: Manufacturer
        lblManufacturer = new Label();
        lblManufacturer.AutoSize = true;
        lblManufacturer.Location = new Point(17, 54);
        lblManufacturer.TabIndex = 6;
        lblManufacturer.Text = "Manufacturer:";
        Controls.Add(lblManufacturer);

        // Combo Box: Manufacturers
        cbxManufacturers = new ComboBox();
        cbxManufacturers.DropDownStyle = ComboBoxStyle.DropDownList;
        cbxManufacturers.FormattingEnabled = true;
        cbxManufacturers.Location = new Point(96, 50);
        cbxManufacturers.Size = new System.Drawing.Size(200, 21);
        cbxManufacturers.TabIndex = 7;
        Controls.Add(cbxManufacturers);

        // Button: New Manufacturer
        btnNewManufacturer = new Button();
        btnNewManufacturer.Location = new Point(302, 50);
        btnNewManufacturer.Size = new System.Drawing.Size(50, 23);
        btnNewManufacturer.TabIndex = 21;
        btnNewManufacturer.Text = "New...";
        btnNewManufacturer.Click += new System.EventHandler(btnNewManufacturerClick);
        Controls.Add(btnNewManufacturer);

        // Label: Category
        lblCategory = new Label();
        lblCategory.AutoSize = true;
        lblCategory.Location = new Point(17, 82);
        lblCategory.TabIndex = 8;
        lblCategory.Text = "Category:";
        Controls.Add(lblCategory);

        // Combo Box: Categories
        cbxCategories = new ComboBox();
        cbxCategories.DropDownStyle = ComboBoxStyle.DropDownList;
        cbxCategories.FormattingEnabled = true;
        cbxCategories.Location = new Point(96, 79);
        cbxCategories.Size = new System.Drawing.Size(200, 21);
        cbxCategories.TabIndex = 9;
        Controls.Add(cbxCategories);

        // Button: New Category
        btnNewCategory = new Button();
        btnNewCategory.Location = new Point(302, 79);
        btnNewCategory.Size = new System.Drawing.Size(50, 23);
        btnNewCategory.TabIndex = 22;
        btnNewCategory.Text = "New...";
        btnNewCategory.Click += new System.EventHandler(btnNewCategoryClick);
        Controls.Add(btnNewCategory);

        // Label: Sub-Category
        lblSubCategory = new Label();
        lblSubCategory.AutoSize = true;
        lblSubCategory.Location = new Point(17, 113);
        lblSubCategory.TabIndex = 10;
        lblSubCategory.Text = "Sub-Category:";
        Controls.Add(lblSubCategory);

        // Combo Box: Sub-Categories
        cbxSubCategories = new ComboBox();
        cbxSubCategories.DropDownStyle = ComboBoxStyle.DropDownList;
        cbxSubCategories.FormattingEnabled = true;
        cbxSubCategories.Location = new Point(96, 109);
        cbxSubCategories.Size = new System.Drawing.Size(200, 21);
        cbxSubCategories.TabIndex = 11;
        Controls.Add(cbxSubCategories);

        // Button: New Sub-Category
        btnNewSubCategory = new Button();
        btnNewSubCategory.Location = new Point(302, 109);
        btnNewSubCategory.Size = new System.Drawing.Size(50, 23);
        btnNewSubCategory.TabIndex = 23;
        btnNewSubCategory.Text = "New...";
        btnNewSubCategory.Click += new System.EventHandler(btnNewSubCategoryClick);
        Controls.Add(btnNewSubCategory);

        // Label: Item Name
        lblItemName = new Label();
        lblItemName.AutoSize = true;
        lblItemName.Location = new Point(17, 142);
        lblItemName.TabIndex = 12;
        lblItemName.Text = "Item Name:";
        Controls.Add(lblItemName);

        // Text Box: Item Name
        txtItemName = new TextBox();
        txtItemName.Location = new Point(96, 139);
        txtItemName.Size = new System.Drawing.Size(256, 20);
        txtItemName.TabIndex = 13;
        Controls.Add(txtItemName);

        // Label: Item Size
        lblItemSize = new Label();
        lblItemSize.AutoSize = true;
        lblItemSize.Location = new Point(17, 172);
        lblItemSize.TabIndex = 14;
        lblItemSize.Text = "Item Size:";
        Controls.Add(lblItemSize);

        // Text Box: Item Size
        txtItemSize = new TextBox();
        txtItemSize.Location = new Point(96, 169);
        txtItemSize.Size = new System.Drawing.Size(256, 20);
        txtItemSize.TabIndex = 15;
        Controls.Add(txtItemSize);

        // Label: Unit Price
        lblUnitPrice = new Label();
        lblUnitPrice.AutoSize = true;
        lblUnitPrice.Location = new Point(17, 201);
        lblUnitPrice.TabIndex = 16;
        lblUnitPrice.Text = "Unit Price:";
        Controls.Add(lblUnitPrice);

        // Text Box: Unit Price
        txtUnitPrice = new TextBox();
        txtUnitPrice.Location = new Point(96, 198);
        txtUnitPrice.Size = new System.Drawing.Size(94, 20);
        txtUnitPrice.TabIndex = 17;
        txtUnitPrice.Text = "0.00";
        txtUnitPrice.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtUnitPrice);

        // Label: Discount Rate
        lblDiscountRate = new Label();
        lblDiscountRate.AutoSize = true;
        lblDiscountRate.Location = new Point(200, 201);
        lblDiscountRate.Size = new System.Drawing.Size(78, 13);
        lblDiscountRate.TabIndex = 18;
        lblDiscountRate.Text = "Discount Rate:";
        Controls.Add(lblDiscountRate);

        // Text Box: Discount Rate
        txtDiscountRate = new TextBox(); 
        txtDiscountRate.Location = new Point(284, 198);
        txtDiscountRate.Size = new System.Drawing.Size(47, 20);
        txtDiscountRate.TabIndex = 19;
        txtDiscountRate.Text = "0.00";
        txtDiscountRate.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtDiscountRate);

        // Label: Discount Percent
        lblDiscountPercent = new Label();
        lblDiscountPercent.AutoSize = true;
        lblDiscountPercent.Location = new Point(334, 201);
        lblDiscountPercent.TabIndex = 20;
        lblDiscountPercent.Text = "%";
        Controls.Add(lblDiscountPercent);

        // Button: Submit
        btnSubmit = new Button();
        btnSubmit.Location = new Point(113, 236);
        btnSubmit.Size = new System.Drawing.Size(75, 23);
        btnSubmit.TabIndex = 25;
        btnSubmit.Text = "Submit";
        btnSubmit.Click += new System.EventHandler(btnSubmitClick);
        Controls.Add(btnSubmit);

        // Button: Reset
        btnReset = new Button();
        btnReset.Location = new Point(194, 236);
        btnReset.Size = new System.Drawing.Size(75, 23);
        btnReset.TabIndex = 26;
        btnReset.Text = "Reset";
        btnReset.Click += new System.EventHandler(btnResetClick);
        Controls.Add(btnReset);

        // Button: Close
        btnClose = new Button();
        btnClose.Location = new Point(275, 236);
        btnClose.Size = new System.Drawing.Size(75, 23);
        btnClose.TabIndex = 24;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);
        Controls.Add(btnClose);

        // Dialog Box: New Store Item
        ClientSize = new System.Drawing.Size(372, 280);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        ShowInTaskbar = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - New Store Item";
        Load += new System.EventHandler(StoreItemLoad);
    }

    private void PopulateStoreItem()
    {
        Random rndNumber = new Random();
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        // Set some default values on the New Store Item dialog box before the user opens it
        // Create a random item number. The user can change it if necessary
        txtItemNumber.Text = rndNumber.Next(100000, 999999).ToString();

        cbxManufacturers.Items.Clear();
        cbxCategories.Items.Clear();
        cbxSubCategories.Items.Clear();

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlCategories = xdStoreItems.SelectNodes("/StoreItems/StoreItem/Category");
                XmlNodeList xnlSubCategories = xdStoreItems.SelectNodes("/StoreItems/StoreItem/SubCategory");
                XmlNodeList xnlManufacturers = xdStoreItems.SelectNodes("/StoreItems/StoreItem/Manufacturer");

                foreach (XmlNode xnManufacturer in xnlManufacturers)
                {
                    if (!cbxManufacturers.Items.Contains(xnManufacturer.InnerText))
                        cbxManufacturers.Items.Add(xnManufacturer.InnerText);
                }

                foreach (XmlNode xnCategory in xnlCategories)
                {
                    if (!cbxCategories.Items.Contains(xnCategory.InnerText))
                        cbxCategories.Items.Add(xnCategory.InnerText);
                }

                foreach (XmlNode xnSubCategory in xnlSubCategories)
                {
                    if (!cbxSubCategories.Items.Contains(xnSubCategory.InnerText))
                        cbxSubCategories.Items.Add(xnSubCategory.InnerText);
                }

                cbxManufacturers.Sorted = true;
                cbxCategories.Sorted = true;
                cbxSubCategories.Sorted = true;

                cbxManufacturers.Text = "N/A";
                cbxCategories.Text = "N/A";
                cbxSubCategories.Text = "N/A";
                txtItemName.Text = "";
                txtItemSize.Text = "";
                txtUnitPrice.Text = "0.00";
                txtDiscountRate.Text = "";
            }
        }
    }

    private void StoreItemLoad(object sender, EventArgs e)
    {
        PopulateStoreItem();
    }

    private void btnNewManufacturerClick(object sender, EventArgs e)
    {
        // bool ManufacturerFound = false;
        Manufacturer man = new Manufacturer();

        // Show the New Manufacturer dialog box.
        // Find out if the user clicked OK after using the dialog box
        if (man.ShowDialog() == DialogResult.OK)
        {
            // If the user clicked OK...
            // ... if the Manufacturer text box was empty, do nothing
            if (string.IsNullOrEmpty(man.txtManufacturer.Text))
            {
                MessageBox.Show("You must enter a manufacturer's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxManufacturers.Items.Contains(man.txtManufacturer.Text))
                {
                    cbxManufacturers.Items.Add(man.txtManufacturer.Text);
                    cbxManufacturers.Text = man.txtManufacturer.Text;
                }
            }
        }
    }

    private void btnNewCategoryClick(object sender, EventArgs e)
    {
        Category cat = new Category();

        if (cat.ShowDialog() == DialogResult.OK)
        {
            if (string.IsNullOrEmpty(cat.txtCategory.Text))
            {
                MessageBox.Show("You must enter a category's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxCategories.Items.Contains(cat.txtCategory.Text))
                {
                    cbxCategories.Items.Add(cat.txtCategory.Text);
                    cbxCategories.Text = cat.txtCategory.Text;
                }
            }
        }
    }

    private void btnNewSubCategoryClick(object sender, EventArgs e)
    {
        SubCategory sc = new SubCategory();

        if (sc.ShowDialog() == DialogResult.OK)
        {
            if (string.IsNullOrEmpty(sc.txtSubCategory.Text))
            {
                MessageBox.Show("You must enter a sub-category's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxSubCategories.Items.Contains(sc.txtSubCategory.Text))
                {
                    cbxSubCategories.Items.Add(sc.txtSubCategory.Text);
                    cbxSubCategories.Text = sc.txtSubCategory.Text;
                }
            }
        }
    }

    private void btnResetClick(object sender, EventArgs e)
    {
        PopulateStoreItem();
    }

    private void btnSubmitClick(object sender, EventArgs e)
    {
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        if (string.IsNullOrEmpty(txtItemNumber.Text))
        {
            MessageBox.Show("You must provide at least an item number.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }
        else if (string.IsNullOrEmpty(txtItemName.Text))
        {
            MessageBox.Show("You must specify the name of the item or a (short) description.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }

        if (!File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Create, FileAccess.Write))
            {                
            xdStoreItems.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                                 "<StoreItems></StoreItems>");
            xdStoreItems.Save(fsStoreItems);
            }
        }
        using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
        {
            xdStoreItems.Load(fsStoreItems);
        }

        using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Create, FileAccess.Write))
        {
            XmlElement xeStoreItem = xdStoreItems.CreateElement("StoreItem");
            xeStoreItem.InnerXml = "<ItemNumber>" + txtItemNumber.Text + "</ItemNumber>" +
                                   "<Manufacturer>" + cbxManufacturers.Text + "</Manufacturer>" +
                                   "<Category>" + cbxCategories.Text + "</Category>" +
                                   "<SubCategory>" + cbxSubCategories.Text + "</SubCategory>" +
                                   "<ItemName>" + txtItemName.Text + "</ItemName>" +
                                   "<ItemSize>" + txtItemSize.Text + "</ItemSize>" +
                                   "<UnitPrice>" + txtUnitPrice.Text + "</UnitPrice>" +
                                   "<DiscountRate>" + txtDiscountRate.Text + "</DiscountRate>";

            xdStoreItems.DocumentElement.AppendChild(xeStoreItem);

            xdStoreItems.Save(fsStoreItems);
        }

        PopulateStoreItem();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }
}

On the main menu, click File -> New
When asked whether you want to save, click Save
In the top combo box, make sure FunDS1 is selected Set the Save As Type combo box to All Files
Set the File Name to StoreItemNew.cs
Click Save

Editing a Store Item

Editing an item consists of changing any of its aspects. Since this is an XML-based application, you can simply open a file in a text editor and change anything. As for us, we will provide a form that can be used to enter an item number and click a button to find it. If the item is found, the employee can make any changes, and save it.

Practical Learning: Editing a Store Item

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class StoreItemEditor : Form
{
    private Label lblItemNumber;
    public TextBox txtItemNumber;
    private Button btnFind;
    private Label lblManufacturer;
    public ComboBox cbxManufacturers;
    private Button btnNewManufacturer;
    private Label lblCategory;
    public ComboBox cbxCategories;
    private Button btnNewCategory;
    private Label lblSubCategory;
    public ComboBox cbxSubCategories;
    private Button btnNewSubCategory;
    private Label lblItemName;
    public TextBox txtItemName;
    private Label lblItemSize;
    public TextBox txtItemSize;
    private Label lblUnitPrice;
    public TextBox txtUnitPrice;
    private Label lblDiscountRate;
    public TextBox txtDiscountRate;
    private Label lblDiscountPercent;
    private Button btnUpdate;
    private Button btnClose;

    public StoreItemEditor()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Item Number
        lblItemNumber = new Label();
        lblItemNumber.AutoSize = true;
        lblItemNumber.Location = new Point(17, 24);
        lblItemNumber.TabIndex = 2;
        lblItemNumber.Text = "Item Number:";
        Controls.Add(lblItemNumber);

        txtItemNumber = new TextBox();
        txtItemNumber.Location = new Point(96, 21);
        txtItemNumber.Size = new System.Drawing.Size(75, 20);
        txtItemNumber.TabIndex = 3;
        Controls.Add(txtItemNumber);

        // Button: New Find
        btnFind = new Button();
        btnFind.Location = new Point(180, 20);
        btnFind.Size = new System.Drawing.Size(50, 23);
        btnFind.TabIndex = 21;
        btnFind.Text = "Find";
        btnFind.Click += new System.EventHandler(btnFindClick);
        Controls.Add(btnFind);

        // Label: Manufacturer
        lblManufacturer = new Label();
        lblManufacturer.AutoSize = true;
        lblManufacturer.Location = new Point(17, 54);
        lblManufacturer.TabIndex = 6;
        lblManufacturer.Text = "Manufacturer:";
        Controls.Add(lblManufacturer);

        // Combo Box: Manufacturers
        cbxManufacturers = new ComboBox();
        cbxManufacturers.Location = new Point(96, 50);
        cbxManufacturers.Size = new System.Drawing.Size(200, 21);
        cbxManufacturers.TabIndex = 7;
        Controls.Add(cbxManufacturers);

        // Button: New Manufacturer
        btnNewManufacturer = new Button();
        btnNewManufacturer.Location = new Point(302, 49);
        btnNewManufacturer.Size = new System.Drawing.Size(50, 23);
        btnNewManufacturer.TabIndex = 21;
        btnNewManufacturer.Text = "New...";
        btnNewManufacturer.Click += new System.EventHandler(btnNewManufacturerClick);
        Controls.Add(btnNewManufacturer);

        // Label: Category
        lblCategory = new Label();
        lblCategory.AutoSize = true;
        lblCategory.Location = new Point(17, 82);
        lblCategory.TabIndex = 8;
        lblCategory.Text = "Category:";
        Controls.Add(lblCategory);

        // Combo Box: Categories
        cbxCategories = new ComboBox();
        cbxCategories.Location = new Point(96, 79);
        cbxCategories.Size = new System.Drawing.Size(200, 21);
        cbxCategories.TabIndex = 9;
        Controls.Add(cbxCategories);

        // Button: New Category
        btnNewCategory = new Button();
        btnNewCategory.Location = new Point(302, 77);
        btnNewCategory.Size = new System.Drawing.Size(50, 23);
        btnNewCategory.TabIndex = 22;
        btnNewCategory.Text = "New...";
        btnNewCategory.Click += new System.EventHandler(btnNewCategoryClick);
        Controls.Add(btnNewCategory);

        // Label: Sub-Category
        lblSubCategory = new Label();
        lblSubCategory.AutoSize = true;
        lblSubCategory.Location = new Point(17, 113);
        lblSubCategory.TabIndex = 10;
        lblSubCategory.Text = "Sub-Category:";
        Controls.Add(lblSubCategory);

        // Combo Box: Sub-Categories
        cbxSubCategories = new ComboBox();
        cbxSubCategories.Location = new Point(96, 109);
        cbxSubCategories.Size = new System.Drawing.Size(200, 21);
        cbxSubCategories.TabIndex = 11;
        Controls.Add(cbxSubCategories);

        // Button: New Sub-Category
        btnNewSubCategory = new Button();
        btnNewSubCategory.Location = new Point(302, 107);
        btnNewSubCategory.Size = new System.Drawing.Size(50, 23);
        btnNewSubCategory.TabIndex = 23;
        btnNewSubCategory.Text = "New...";
        btnNewSubCategory.Click += new System.EventHandler(btnNewSubCategoryClick);
        Controls.Add(btnNewSubCategory);

        // Label: Item Name
        lblItemName = new Label();
        lblItemName.AutoSize = true;
        lblItemName.Location = new Point(17, 142);
        lblItemName.TabIndex = 12;
        lblItemName.Text = "Item Name:";
        Controls.Add(lblItemName);

        // Text Box: Item Name
        txtItemName = new TextBox();
        txtItemName.Location = new Point(96, 139);
        txtItemName.Size = new System.Drawing.Size(256, 20);
        txtItemName.TabIndex = 13;
        Controls.Add(txtItemName);

        // Label: Item Size
        lblItemSize = new Label();
        lblItemSize.AutoSize = true;
        lblItemSize.Location = new Point(17, 172);
        lblItemSize.TabIndex = 14;
        lblItemSize.Text = "Item Size:";
        Controls.Add(lblItemSize);

        // Text Box: Item Size
        txtItemSize = new TextBox();
        txtItemSize.Location = new Point(96, 169);
        txtItemSize.Size = new System.Drawing.Size(256, 20);
        txtItemSize.TabIndex = 15;
        Controls.Add(txtItemSize);

        // Label: Unit Price
        lblUnitPrice = new Label();
        lblUnitPrice.AutoSize = true;
        lblUnitPrice.Location = new Point(17, 201);
        lblUnitPrice.TabIndex = 16;
        lblUnitPrice.Text = "Unit Price:";
        Controls.Add(lblUnitPrice);

        // Text Box: Unit Price
        txtUnitPrice = new TextBox();
        txtUnitPrice.Location = new Point(96, 198);
        txtUnitPrice.Size = new System.Drawing.Size(94, 20);
        txtUnitPrice.TabIndex = 17;
        txtUnitPrice.Text = "0.00";
        txtUnitPrice.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtUnitPrice);

        // Label: Discount Rate
        lblDiscountRate = new Label(); 
        lblDiscountRate.AutoSize = true;
        lblDiscountRate.Location = new Point(200, 201);
        lblDiscountRate.Size = new System.Drawing.Size(78, 13);
        lblDiscountRate.TabIndex = 18;
        lblDiscountRate.Text = "Discount Rate:";
        Controls.Add(lblDiscountRate);

        // Text Box: Discount Rate
        txtDiscountRate = new TextBox();
        txtDiscountRate.Location = new Point(284, 198);
        txtDiscountRate.Size = new System.Drawing.Size(47, 20);
        txtDiscountRate.TabIndex = 19;
        txtDiscountRate.Text = "0.00";
        txtDiscountRate.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtDiscountRate);

        // Label: Discount Percent
        lblDiscountPercent = new Label();
        lblDiscountPercent.AutoSize = true;
        lblDiscountPercent.Location = new Point(334, 201);
        lblDiscountPercent.TabIndex = 20;
        lblDiscountPercent.Text = "%";
        Controls.Add(lblDiscountPercent);

        // Button: Update
        btnUpdate = new Button();
        btnUpdate.Location = new Point(196, 231);
        btnUpdate.Size = new System.Drawing.Size(75, 23);
        btnUpdate.TabIndex = 25;
        btnUpdate.Text = "Update";
        btnUpdate.Click += new System.EventHandler(btnUpdateClick);
        Controls.Add(btnUpdate);

        // Button: Close
        btnClose = new Button();
        btnClose.Location = new Point(275, 231);
        btnClose.Size = new System.Drawing.Size(75, 23);
        btnClose.TabIndex = 24;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);
        Controls.Add(btnClose);

        // Dialog Box: New Store Item
        ClientSize = new System.Drawing.Size(372, 276);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        ShowInTaskbar = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - Edit Store Item";
        Load += new System.EventHandler(StoreItemLoad);
    }

    private void PopulateStoreItem()
    {
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        cbxManufacturers.Items.Clear();
        cbxCategories.Items.Clear();
        cbxSubCategories.Items.Clear();

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlCategories = xdStoreItems.SelectNodes("/StoreItems/StoreItem/Category");
                XmlNodeList xnlSubCategories = xdStoreItems.SelectNodes("/StoreItems/StoreItem/SubCategory");
                XmlNodeList xnlManufacturers = xdStoreItems.SelectNodes("/StoreItems/StoreItem/Manufacturer");

                foreach (XmlNode xnManufacturer in xnlManufacturers)
                {
                    if (!cbxManufacturers.Items.Contains(xnManufacturer.InnerText))
                        cbxManufacturers.Items.Add(xnManufacturer.InnerText);
                }

                foreach (XmlNode xnCategory in xnlCategories)
                {
                    if (!cbxCategories.Items.Contains(xnCategory.InnerText))
                        cbxCategories.Items.Add(xnCategory.InnerText);
                }

                foreach (XmlNode xnSubCategory in xnlSubCategories)
                {
                    if (!cbxSubCategories.Items.Contains(xnSubCategory.InnerText))
                        cbxSubCategories.Items.Add(xnSubCategory.InnerText);
                }

                cbxManufacturers.Sorted = true;
                cbxCategories.Sorted = true;
                cbxSubCategories.Sorted = true;/**/

                cbxManufacturers.Text = "N/A";
                cbxCategories.Text = "N/A";
                cbxSubCategories.Text = "N/A";
                txtItemName.Text = "";
                txtItemSize.Text = "";
                txtUnitPrice.Text = "0.00";
                txtDiscountRate.Text = "0.00";
            }
        }
    }

    private void StoreItemLoad(object sender, EventArgs e)
    {
        PopulateStoreItem();
    }

    private void btnNewManufacturerClick(object sender, EventArgs e)
    {
        // bool ManufacturerFound = false;
        Manufacturer man = new Manufacturer();

        // Show the New Manufacturer dialog box.
        // Find out if the user clicked OK after using the dialog box
        if (man.ShowDialog() == DialogResult.OK)
        {
            // If the user clicked OK...
            // ... if the Manufacturer text box was empty, do nothing
            if (string.IsNullOrEmpty(man.txtManufacturer.Text))
            {
                MessageBox.Show("You must enter a manufacturer's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxManufacturers.Items.Contains(man.txtManufacturer.Text))
                {
                    cbxManufacturers.Items.Add(man.txtManufacturer.Text);
                    cbxManufacturers.Text = man.txtManufacturer.Text;
                }
            }
        }
    }

    private void btnNewCategoryClick(object sender, EventArgs e)
    {
        Category cat = new Category();

        if (cat.ShowDialog() == DialogResult.OK)
        {
            if (string.IsNullOrEmpty(cat.txtCategory.Text))
            {
                MessageBox.Show("You must enter a category's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxCategories.Items.Contains(cat.txtCategory.Text))
                {
                    cbxCategories.Items.Add(cat.txtCategory.Text);
                    cbxCategories.Text = cat.txtCategory.Text;
                }
            }
        }
    }

    private void btnNewSubCategoryClick(object sender, EventArgs e)
    {
        SubCategory sc = new SubCategory();

        if (sc.ShowDialog() == DialogResult.OK)
        {
            if (string.IsNullOrEmpty(sc.txtSubCategory.Text))
            {
                MessageBox.Show("You must enter a sub-category's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxSubCategories.Items.Contains(sc.txtSubCategory.Text))
                {
                    cbxSubCategories.Items.Add(sc.txtSubCategory.Text);
                    cbxSubCategories.Text = sc.txtSubCategory.Text;
                }
            }
        }
    }

    private void btnFindClick(object sender, EventArgs e)
    {
        bool itemFound = false;
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems1.xml";

        if (string.IsNullOrEmpty(txtItemNumber.Text))
        {
            MessageBox.Show("You must provide an item number.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                foreach (XmlNode xnStoreItem in xnlStoreItems)
                {
                    if (xnStoreItem.InnerText == txtItemNumber.Text)
                    {
                        itemFound = true;
                        cbxManufacturers.Text = xnStoreItem.NextSibling.InnerText;
                        cbxCategories.Text    = xnStoreItem.NextSibling.NextSibling.InnerText;
                        cbxSubCategories.Text = xnStoreItem.NextSibling.NextSibling.NextSibling.InnerText;
                        txtItemName.Text      = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtItemSize.Text      = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtUnitPrice.Text     = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtDiscountRate.Text  = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;

                        return;
                    }
                }

                if (itemFound == false)
                    MessageBox.Show("There is no item with that number.",
                                    "FunDS - Fun Department Store",
                                    MessageBoxButtons.OK,
                                    MessageBoxIcon.Information);
            }
        }
    }

    private void btnUpdateClick(object sender, EventArgs e)
    {
        bool itemFound = false;
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        if (string.IsNullOrEmpty(txtItemNumber.Text))
        {
            MessageBox.Show("You must provide an item number.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                foreach (XmlNode xnStoreItem in xnlStoreItems)
                {
                    if (xnStoreItem.InnerText == txtItemNumber.Text)
                    {
                        itemFound = true;
                        xnStoreItem.ParentNode.InnerXml = "<ItemNumber>" + txtItemNumber.Text + "</ItemNumber>" +
                                                          "<Manufacturer>" + cbxManufacturers.Text + "</Manufacturer>" +
                                                          "<Category>" + cbxCategories.Text + "</Category>" +
                                                          "<SubCategory>" + cbxSubCategories.Text + "</SubCategory>" +
                                                          "<ItemName>" + txtItemName.Text + "</ItemName>" +
                                                          "<ItemSize>" + txtItemSize.Text + "</ItemSize>" +
                                                          "<UnitPrice>" + txtUnitPrice.Text + "</UnitPrice>" +
                                                          "<DiscountRate>" + txtDiscountRate.Text + "</DiscountRate>"; ;
                        break;
                    }
                }
            }

            if (itemFound == true)
            {
                using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Create, FileAccess.Write))
                {
                    xdStoreItems.Save(fsStoreItems);
                    MessageBox.Show("The store item has been updated.",
                                    "FunDS - Fun Department Store",
                                    MessageBoxButtons.OK,
                                    MessageBoxIcon.Information);
                }
            }
        }

        PopulateStoreItem();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }
}

On the main menu, click File -> New
When asked whether you want to save, click Save
In the top combo box, make sure the FunDS1 folder is displaying, Set the Save As Type to All Files
Set the name to StoreItemEditor.cs
Click Save

Deleting a Store Item

To make sure we cover most aspects of data maintenance are covered, we will give the company the ability to delete an item from the inventory.

Practical Learning: Deleting an Item

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class StoreItemDelete : Form
{
    private Label lblItemNumber;
    public TextBox txtItemNumber;
    private Button btnFind;
    private Label lblManufacturer;
    public ComboBox cbxManufacturers;
    private Button btnNewManufacturer;
    private Label lblCategory;
    public ComboBox cbxCategories;
    private Button btnNewCategory;
    private Label lblSubCategory;
    public ComboBox cbxSubCategories;
    private Button btnNewSubCategory;
    private Label lblItemName;
    public TextBox txtItemName;
    private Label lblItemSize;
    public TextBox txtItemSize;
    private Label lblUnitPrice;
    public TextBox txtUnitPrice;
    private Label lblDiscountRate;
    public TextBox txtDiscountRate;
    private Label lblDiscountPercent;
    private Button btnDelete;
    private Button btnClose;

    public StoreItemDelete()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Item Number
        lblItemNumber = new Label();
        lblItemNumber.AutoSize = true;
        lblItemNumber.Location = new Point(17, 24);
        lblItemNumber.TabIndex = 2;
        lblItemNumber.Text = "Item Number:";
        Controls.Add(lblItemNumber);

        txtItemNumber = new TextBox();
        txtItemNumber.Location = new Point(96, 21);
        txtItemNumber.Size = new System.Drawing.Size(75, 20);
        txtItemNumber.TabIndex = 3;
        Controls.Add(txtItemNumber);

        // Button: New Find
        btnFind = new Button();
        btnFind.Location = new Point(180, 20);
        btnFind.Size = new System.Drawing.Size(50, 23);
        btnFind.TabIndex = 21;
        btnFind.Text = "Find";
        btnFind.Click += new System.EventHandler(btnFindClick);
        Controls.Add(btnFind);

        // Label: Manufacturer
        lblManufacturer = new Label();
        lblManufacturer.AutoSize = true;
        lblManufacturer.Location = new Point(17, 54);
        lblManufacturer.TabIndex = 6;
        lblManufacturer.Text = "Manufacturer:";
        Controls.Add(lblManufacturer);

        // Combo Box: Manufacturers
        cbxManufacturers = new ComboBox();
        cbxManufacturers.Location = new Point(96, 50);
        cbxManufacturers.Size = new System.Drawing.Size(200, 21);
        cbxManufacturers.TabIndex = 7;
        Controls.Add(cbxManufacturers);

        // Button: New Manufacturer
        btnNewManufacturer = new Button();
        btnNewManufacturer.Location = new Point(302, 49);
        btnNewManufacturer.Size = new System.Drawing.Size(50, 23);
        btnNewManufacturer.TabIndex = 21;
        btnNewManufacturer.Text = "New...";
        btnNewManufacturer.Click += new System.EventHandler(btnNewManufacturerClick);
        Controls.Add(btnNewManufacturer);

        // Label: Category
        lblCategory = new Label();
        lblCategory.AutoSize = true;
        lblCategory.Location = new Point(17, 82);
        lblCategory.TabIndex = 8;
        lblCategory.Text = "Category:";
        Controls.Add(lblCategory);

        // Combo Box: Categories
        cbxCategories = new ComboBox();
        cbxCategories.Location = new Point(96, 79);
        cbxCategories.Size = new System.Drawing.Size(200, 21);
        cbxCategories.TabIndex = 9;
        Controls.Add(cbxCategories);

        // Button: New Category
        btnNewCategory = new Button();
        btnNewCategory.Location = new Point(302, 77);
        btnNewCategory.Size = new System.Drawing.Size(50, 23);
        btnNewCategory.TabIndex = 22;
        btnNewCategory.Text = "New...";
        btnNewCategory.Click += new System.EventHandler(btnNewCategoryClick);
        Controls.Add(btnNewCategory);

        // Label: Sub-Category
        lblSubCategory = new Label();
        lblSubCategory.AutoSize = true;
        lblSubCategory.Location = new Point(17, 113);
        lblSubCategory.TabIndex = 10;
        lblSubCategory.Text = "Sub-Category:";
        Controls.Add(lblSubCategory);

        // Combo Box: Sub-Categories
        cbxSubCategories = new ComboBox();
        cbxSubCategories.Location = new Point(96, 109);
        cbxSubCategories.Size = new System.Drawing.Size(200, 21);
        cbxSubCategories.TabIndex = 11;
        Controls.Add(cbxSubCategories);

        // Button: New Sub-Category
        btnNewSubCategory = new Button();
        btnNewSubCategory.Location = new Point(302, 107);
        btnNewSubCategory.Size = new System.Drawing.Size(50, 23);
        btnNewSubCategory.TabIndex = 23;
        btnNewSubCategory.Text = "New...";
        btnNewSubCategory.Click += new System.EventHandler(btnNewSubCategoryClick);
        Controls.Add(btnNewSubCategory);

        // Label: Item Name
        lblItemName = new Label();
        lblItemName.AutoSize = true;
        lblItemName.Location = new Point(17, 142);
        lblItemName.TabIndex = 12;
        lblItemName.Text = "Item Name:";
        Controls.Add(lblItemName);

        // Text Box: Item Name
        txtItemName = new TextBox();
        txtItemName.Location = new Point(96, 139);
        txtItemName.Size = new System.Drawing.Size(256, 20);
        txtItemName.TabIndex = 13;
        Controls.Add(txtItemName);

        // Label: Item Size
        lblItemSize = new Label();
        lblItemSize.AutoSize = true;
        lblItemSize.Location = new Point(17, 172);
        lblItemSize.TabIndex = 14;
        lblItemSize.Text = "Item Size:";
        Controls.Add(lblItemSize);

        // Text Box: Item Size
        txtItemSize = new TextBox();
        txtItemSize.Location = new Point(96, 169);
        txtItemSize.Size = new System.Drawing.Size(256, 20);
        txtItemSize.TabIndex = 15;
        Controls.Add(txtItemSize);

        // Label: Unit Price
        lblUnitPrice = new Label();
        lblUnitPrice.AutoSize = true;
        lblUnitPrice.Location = new Point(17, 201);
        lblUnitPrice.TabIndex = 16;
        lblUnitPrice.Text = "Unit Price:";
        Controls.Add(lblUnitPrice);

        // Text Box: Unit Price
        txtUnitPrice = new TextBox();
        txtUnitPrice.Location = new Point(96, 198);
        txtUnitPrice.Size = new System.Drawing.Size(94, 20);
        txtUnitPrice.TabIndex = 17;
        txtUnitPrice.Text = "0.00";
        txtUnitPrice.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtUnitPrice);

        // Label: Discount Rate
        lblDiscountRate = new Label();
        lblDiscountRate.AutoSize = true;
        lblDiscountRate.Location = new Point(200, 201);
        lblDiscountRate.Size = new System.Drawing.Size(78, 13);
        lblDiscountRate.TabIndex = 18;
        lblDiscountRate.Text = "Discount Rate:";
        Controls.Add(lblDiscountRate);

        // Text Box: Discount Rate
        txtDiscountRate = new TextBox();
        txtDiscountRate.Location = new Point(284, 198);
        txtDiscountRate.Size = new System.Drawing.Size(47, 20);
        txtDiscountRate.TabIndex = 19;
        txtDiscountRate.Text = "0.00";
        txtDiscountRate.TextAlign = HorizontalAlignment.Right;
        Controls.Add(txtDiscountRate);

        // Label: Discount Percent
        lblDiscountPercent = new Label();
        lblDiscountPercent.AutoSize = true;
        lblDiscountPercent.Location = new Point(334, 201);
        lblDiscountPercent.TabIndex = 20;
        lblDiscountPercent.Text = "%";
        Controls.Add(lblDiscountPercent);

        // Button: Delete
        btnDelete = new Button();
        btnDelete.Location = new Point(196, 231);
        btnDelete.Size = new System.Drawing.Size(75, 23);
        btnDelete.TabIndex = 25;
        btnDelete.Text = "Delete";
        btnDelete.Click += new System.EventHandler(btnDeleteClick);
        Controls.Add(btnDelete);

        // Button: Close
        btnClose = new Button();
        btnClose.Location = new Point(275, 231);
        btnClose.Size = new System.Drawing.Size(75, 23);
        btnClose.TabIndex = 24;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);
        Controls.Add(btnClose);

        // Dialog Box: New Store Item
        ClientSize = new System.Drawing.Size(372, 276);
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;
        ShowInTaskbar = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - Edit Store Item";
        Load += new System.EventHandler(StoreItemLoad);
    }

    private void PopulateStoreItem()
    {
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        cbxManufacturers.Items.Clear();
        cbxCategories.Items.Clear();
        cbxSubCategories.Items.Clear();

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlCategories = xdStoreItems.SelectNodes("/StoreItems/StoreItem/Category");
                XmlNodeList xnlSubCategories = xdStoreItems.SelectNodes("/StoreItems/StoreItem/SubCategory");
                XmlNodeList xnlManufacturers = xdStoreItems.SelectNodes("/StoreItems/StoreItem/Manufacturer");

                foreach (XmlNode xnManufacturer in xnlManufacturers)
                {
                    if (!cbxManufacturers.Items.Contains(xnManufacturer.InnerText))
                        cbxManufacturers.Items.Add(xnManufacturer.InnerText);
                }

                foreach (XmlNode xnCategory in xnlCategories)
                {
                    if (!cbxCategories.Items.Contains(xnCategory.InnerText))
                        cbxCategories.Items.Add(xnCategory.InnerText);
                }

                foreach (XmlNode xnSubCategory in xnlSubCategories)
                {
                    if (!cbxSubCategories.Items.Contains(xnSubCategory.InnerText))
                        cbxSubCategories.Items.Add(xnSubCategory.InnerText);
                }

                cbxManufacturers.Sorted = true;
                cbxCategories.Sorted = true;
                cbxSubCategories.Sorted = true;/**/

                cbxManufacturers.Text = "N/A";
                cbxCategories.Text = "N/A";
                cbxSubCategories.Text = "N/A";
                txtItemName.Text = "";
                txtItemSize.Text = "";
                txtUnitPrice.Text = "0.00";
                txtDiscountRate.Text = "0.00";
            }
        }
    }

    private void StoreItemLoad(object sender, EventArgs e)
    {
        PopulateStoreItem();
    }

    private void btnNewManufacturerClick(object sender, EventArgs e)
    {
        // bool ManufacturerFound = false;
        Manufacturer man = new Manufacturer();

        // Show the New Manufacturer dialog box.
        // Find out if the user clicked OK after using the dialog box
        if (man.ShowDialog() == DialogResult.OK)
        {
            // If the user clicked OK...
            // ... if the Manufacturer text box was empty, do nothing
            if (string.IsNullOrEmpty(man.txtManufacturer.Text))
            {
                MessageBox.Show("You must enter a manufacturer's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxManufacturers.Items.Contains(man.txtManufacturer.Text))
                {
                    cbxManufacturers.Items.Add(man.txtManufacturer.Text);
                    cbxManufacturers.Text = man.txtManufacturer.Text;
                }
            }
        }
    }

    private void btnNewCategoryClick(object sender, EventArgs e)
    {
        Category cat = new Category();

        if (cat.ShowDialog() == DialogResult.OK)
        {
            if (string.IsNullOrEmpty(cat.txtCategory.Text))
            {
                MessageBox.Show("You must enter a category's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxCategories.Items.Contains(cat.txtCategory.Text))
                {
                    cbxCategories.Items.Add(cat.txtCategory.Text);
                    cbxCategories.Text = cat.txtCategory.Text;
                }
            }
        }
    }

    private void btnNewSubCategoryClick(object sender, EventArgs e)
    {
        SubCategory sc = new SubCategory();

        if (sc.ShowDialog() == DialogResult.OK)
        {
            if (string.IsNullOrEmpty(sc.txtSubCategory.Text))
            {
                MessageBox.Show("You must enter a sub-category's name.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (!cbxSubCategories.Items.Contains(sc.txtSubCategory.Text))
                {
                    cbxSubCategories.Items.Add(sc.txtSubCategory.Text);
                    cbxSubCategories.Text = sc.txtSubCategory.Text;
                }
            }
        }
    }

    private void btnFindClick(object sender, EventArgs e)
    {
        bool itemFound = false;
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems1.xml";

        if (string.IsNullOrEmpty(txtItemNumber.Text))
        {
            MessageBox.Show("You must provide an item number.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                foreach (XmlNode xnStoreItem in xnlStoreItems)
                {
                    if (xnStoreItem.InnerText == txtItemNumber.Text)
                    {
                        itemFound = true;
                        cbxManufacturers.Text = xnStoreItem.NextSibling.InnerText;
                        cbxCategories.Text = xnStoreItem.NextSibling.NextSibling.InnerText;
                        cbxSubCategories.Text = xnStoreItem.NextSibling.NextSibling.NextSibling.InnerText;
                        txtItemName.Text = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtItemSize.Text = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtUnitPrice.Text = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtDiscountRate.Text = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;

                        return;
                    }
                }

                if (itemFound == false)
                    MessageBox.Show("There is no item with that number.",
                                    "FunDS - Fun Department Store",
                                    MessageBoxButtons.OK,
                                    MessageBoxIcon.Information);
            }
        }
    }

    private void btnDeleteClick(object sender, EventArgs e)
    {
        bool itemFound = false;
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems1.xml";

        if (string.IsNullOrEmpty(txtItemNumber.Text))
        {
            MessageBox.Show("You must provide an item number.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                foreach (XmlNode xnStoreItem in xnlStoreItems)
                {
                    if (xnStoreItem.InnerText == txtItemNumber.Text)
                    {
                        itemFound = true;
                        xdStoreItems.DocumentElement.RemoveChild(xnStoreItem.ParentNode);
                        break;
                    }
                }
            }

            if (itemFound == true)
            {
                using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Create, FileAccess.Write))
                {
                    xdStoreItems.Save(fsStoreItems);
                    MessageBox.Show("The store item has been deleted.",
                                    "FunDS - Fun Department Store",
                                    MessageBoxButtons.OK,
                                    MessageBoxIcon.Information);
                }
            }
        }

        PopulateStoreItem();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }
}

On the main menu, click File -> New

When asked whether you want to save, click Save

In the top combo box, make sure the FunDS1 folder is displaying, Set the Save As Type to All Files

Set the File Name to StoreItemDelete.cs
Click Save

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class StoreItems : Form
{
    private ColumnHeader colStoreItemID;
    private ColumnHeader colItemNumber;
    private ColumnHeader colManufacturer;
    private ColumnHeader colCategory;
    private ColumnHeader colSubCategory;
    private ColumnHeader colItemName;
    private ColumnHeader colItemSize;
    private ColumnHeader colUnitPrice;
    private ColumnHeader colDiscountRate;
    private ColumnHeader colDiscountAmount;
    private ColumnHeader colMarkedPrice;
    private ListView lvwStoreItems;
    private Label lblNumberOfItems;
    private TextBox txtNumberOfItems;
    private Button btnNewStoreItem;
    private Button btnEditStoreItem;
    private Button btnDeleteStoreItem;
    private Button btnClose;

    public StoreItems()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Column: umn: Store Item ID
        colStoreItemID = new ColumnHeader();
        colStoreItemID.Text = "Item ID";
        colStoreItemID.Width = 50;

        // Column: umn: Item Number
        colItemNumber = new ColumnHeader();
        colItemNumber.Text = "Item #";
        colItemNumber.TextAlign = HorizontalAlignment.Center;

        // Column: umn: Manufacturer
        colManufacturer = new ColumnHeader();
        colManufacturer.Text = "Manufacturer";
        colManufacturer.Width = 130;

        // Column: umn: Category
        colCategory = new ColumnHeader();
        colCategory.Text = "Category";
        colCategory.Width = 70;

        // Column: umn: Sub-Category
        colSubCategory = new ColumnHeader();
        colSubCategory.Text = "Sub-Category";
        colSubCategory.Width = 80;

        // Column: umn: Item Name
        colItemName = new ColumnHeader();
        colItemName.Text = "Item Name";
        colItemName.Width = 300;

        // Column: umn: Item Size
        colItemSize = new ColumnHeader();
        colItemSize.Text = "Size";
        colItemSize.Width = 80;

        // Column: umn: Unit Price
        colUnitPrice = new ColumnHeader();
        colUnitPrice.Text = "Unit Price";
        colUnitPrice.TextAlign = HorizontalAlignment.Right;

        // Column: umn: Discount Rate
        colDiscountRate = new ColumnHeader();
        colDiscountRate.Text = "Disc Rate";
        colDiscountRate.TextAlign = HorizontalAlignment.Right;
        colDiscountRate.Width = 60;

        // Column: umn: Discount Amount
        colDiscountAmount = new ColumnHeader();
        colDiscountAmount.Text = "Disc Amt";
        colDiscountAmount.TextAlign = HorizontalAlignment.Right;

        // Column: umn: Marked Price
        colMarkedPrice = new ColumnHeader();
        colMarkedPrice.Text = "Marked Price";
        colMarkedPrice.TextAlign = HorizontalAlignment.Right;
        colMarkedPrice.Width = 75;

        lvwStoreItems = new ListView();
        lvwStoreItems.Anchor = AnchorStyles.Top | AnchorStyles.Bottom
                         | AnchorStyles.Left | AnchorStyles.Right;
        lvwStoreItems.Columns.AddRange(new ColumnHeader[]
        {
            colStoreItemID,	colItemNumber, colManufacturer,
            colCategory, colSubCategory, colItemName, colItemSize,
            colUnitPrice, colDiscountRate, colDiscountAmount, colMarkedPrice
        });
        lvwStoreItems.FullRowSelect = true;
        lvwStoreItems.GridLines = true;
        lvwStoreItems.Location = new Point(15, 15);
        lvwStoreItems.Size = new System.Drawing.Size(1050, 340);
        lvwStoreItems.TabIndex = 3;
        lvwStoreItems.View = View.Details;

        lblNumberOfItems = new Label();
        lblNumberOfItems.Anchor = AnchorStyles.Bottom | AnchorStyles.Left;
        lblNumberOfItems.AutoSize = true;
        lblNumberOfItems.Location = new Point(15, 370);
        lblNumberOfItems.TabIndex = 6;
        lblNumberOfItems.Text = "Number of Items:";

        // Text Box: Number of Items
        txtNumberOfItems = new TextBox();
        txtNumberOfItems.Anchor = AnchorStyles.Bottom | AnchorStyles.Left;
        txtNumberOfItems.Location = new Point(111, 368);
        txtNumberOfItems.Size = new System.Drawing.Size(60, 20);
        txtNumberOfItems.TabIndex = 7;
        txtNumberOfItems.TextAlign = HorizontalAlignment.Right;

        btnNewStoreItem = new Button();
        btnNewStoreItem.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
        btnNewStoreItem.Location = new Point(530, 366);
        btnNewStoreItem.Size = new System.Drawing.Size(125, 32);
        btnNewStoreItem.TabIndex = 5;
        btnNewStoreItem.Text = "New Store Item ...";
        btnNewStoreItem.Click += new System.EventHandler(btnNewStoreItemClick);

        // Button: Edit Item
        btnEditStoreItem = new Button();
        btnEditStoreItem.Location = new Point(659, 366);
        btnEditStoreItem.Size = new System.Drawing.Size(125, 32);
        btnEditStoreItem.Text = "Edit Store Item...";
        btnEditStoreItem.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
        btnEditStoreItem.Click += new System.EventHandler(btnEditStoreItemClick);

        // Button: Remove Item
        btnDeleteStoreItem = new Button();
        btnDeleteStoreItem.Location = new Point(792, 366);
        btnDeleteStoreItem.Size = new System.Drawing.Size(125, 32);
        btnDeleteStoreItem.Text = "Delete Store Item...";
        btnDeleteStoreItem.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
        btnDeleteStoreItem.Click += new System.EventHandler(btnDeleteStoreItemClick);

        btnClose = new Button();
        btnClose.Location = new Point(922, 366);
        btnClose.Size = new System.Drawing.Size(125, 32);
        btnClose.TabIndex = 4;
        btnClose.Text = "Close";
        btnClose.Anchor = AnchorStyles.Bottom | AnchorStyles.Right;
        btnClose.Click += new System.EventHandler(btnCloseClick);

        ClientSize = new System.Drawing.Size(1080, 410);

        Controls.Add(txtNumberOfItems);
        Controls.Add(lblNumberOfItems);
        Controls.Add(btnNewStoreItem);
        Controls.Add(btnEditStoreItem);
        Controls.Add(btnDeleteStoreItem);
        Controls.Add(btnClose);
        Controls.Add(lvwStoreItems);

        StartPosition = FormStartPosition.CenterScreen;
        Text = "Fun Department Store - Store Items";
        Load += new System.EventHandler(StoreItemsLoad);
    }

    private void ShowStoreItems()
    {
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        if (File.Exists(strStoreItemsFile))
        {
            lvwStoreItems.Items.Clear();

            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);
                string itemName = "", itemSize = "", strDiscountRate = "";
                string itemNumber = "", manufacturer = "", category = "", subCategory = "";
                double unitPrice = 0.00, discountRate = 0.00, discountAmount = 0.00, markedPrice = 0.00;

                XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                int i = 1;

                foreach (XmlNode xnStoreItem in xnlStoreItems)
                {
                    itemNumber      = xnStoreItem.InnerText;
                    manufacturer    = xnStoreItem.NextSibling.InnerText;
                    category        = xnStoreItem.NextSibling.NextSibling.InnerText;
                    subCategory     = xnStoreItem.NextSibling.NextSibling.NextSibling.InnerText;
                    itemName        = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                    itemSize        = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                    unitPrice       = double.Parse(xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText);
                    strDiscountRate = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;

                    if ((string.IsNullOrEmpty(strDiscountRate)) || (double.Parse(strDiscountRate) <= 0.00))
                    {
                        discountRate = 0.00;
                        discountAmount = 0.00;
                        markedPrice = unitPrice;
                    }
                    else
                    {
                        discountRate = double.Parse(strDiscountRate) / 100.00;
                        discountAmount = unitPrice * discountRate;
                        markedPrice = unitPrice - discountAmount;
                    }

                    ListViewItem lviStoreItem = new ListViewItem(i.ToString());
                    lviStoreItem.SubItems.Add(itemNumber); // Item Number
                    lviStoreItem.SubItems.Add(manufacturer); // Manufacturer
                    lviStoreItem.SubItems.Add(category); // Category
                    lviStoreItem.SubItems.Add(subCategory); // Sub-Category
                    lviStoreItem.SubItems.Add(itemName); // Item Name
                    lviStoreItem.SubItems.Add(itemSize); // Item Size
                    lviStoreItem.SubItems.Add(unitPrice.ToString("F"));

                    if (discountRate == 0.00)
                    {
                        lviStoreItem.SubItems.Add(""); // Discount Rate
                        lviStoreItem.SubItems.Add(""); // Discount Amount
                        lviStoreItem.SubItems.Add(unitPrice.ToString("F")); // Marked Price
                    }
                    else
                    {
                        lviStoreItem.SubItems.Add((discountRate * 100).ToString() + "%");
                        lviStoreItem.SubItems.Add(discountAmount.ToString("F"));
                        lviStoreItem.SubItems.Add(markedPrice.ToString("F")); // Marked Price
                    }
                    
                    lvwStoreItems.Items.Add(lviStoreItem);
                    i++;
                }

                txtNumberOfItems.Text = xnlStoreItems.Count.ToString();
            }
        }
    }

    private void StoreItemsLoad(object sender, EventArgs e)
    {
        ShowStoreItems();
    }

    private void btnNewStoreItemClick(object sender, EventArgs e)
    {
        StoreItemNew sin = new StoreItemNew();
        sin.ShowDialog();

        ShowStoreItems();
    }
    
    private void btnEditStoreItemClick(object sender, EventArgs e)
    {
        StoreItemEditor sie = new StoreItemEditor();
        sie.ShowDialog();

        ShowStoreItems();
    }

    private void btnDeleteStoreItemClick(object sender, EventArgs e)
    {
        StoreItemDelete sid = new StoreItemDelete();
        sid.ShowDialog();

        ShowStoreItems();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }
}

On the main menu, click File -> New

When asked whether you want to save, click Save

In the top combo box, make sure the FunDS1 folder is displaying, Set the Save As Type to All Files

Set the File Name to Inventory.cs

Save the file

The Point of Sale

A poinit of sale is the workstation where customers purchases are handled. Point of sales used to be a big issue. You had to purchase special machines and have a special setup. Although you still need setup, you can build the whole thing yourself (but we will not discuss all of that this time).

In our application, when a customer brings one or more items to check out, the cashier (or employee) will enter each item number in a text box and press enter. This will display information about the item, including the discount if any. The employee will do this for all items brought by the customer. The employee will also have the ability to remove an item. When all items have been entered, the employee can save the order and start another order or purchase.

Practical Learning: Creating a Point of Sale Tool

In the empty document, type the following code:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class NewShoppingSession : Form
{
    private Label lblItemNumberSelected;
    private TextBox txtItemNumberSelected;
    private Label lblReceiptNumber;
    private TextBox txtReceiptNumber;

    private ColumnHeader colItemNumber;
    private ColumnHeader colItemName;
    private ColumnHeader colItemSize;
    private ColumnHeader colUnitPrice;
    private ColumnHeader colDiscountRate;
    private ColumnHeader colDiscountAmount;
    private ColumnHeader colSalePrice;
    private ListView lvwSoldItems;

    private TextBox txtEmployeeNumber;
    private Label lblEmployeeNumber;
    private DateTimePicker dtpSaleDate;
    private Label lblSaleTime;
    private TextBox txtAmountTendered;
    private Label lblTendered;
    private TextBox txtChange;
    private Label lblChange;
    private TextBox txtOrderTotal;
    private Label lblOrderTotal;
    private TextBox txtEmployeeName;
    private Button btnSubmit;
    private Button btnReset;
    private TextBox txtItemNumberRemove;
    private Label lblItemNumberToRemove;
    private Button btnRemoveItem;
    private Button btnClose;

    private Timer tmrDateTime;

    public NewShoppingSession()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Item Number to Add
        lblItemNumberSelected = new Label();
        lblItemNumberSelected.AutoSize = true;
        lblItemNumberSelected.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblItemNumberSelected.Location = new Point(16, 22);
        lblItemNumberSelected.TabIndex = 2;
        lblItemNumberSelected.Text = "Item # to Add:";

        // Text Box: Item Number to Add
        txtItemNumberSelected = new TextBox();
        txtItemNumberSelected.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtItemNumberSelected.Location = new Point(235, 18);
        txtItemNumberSelected.Size = new System.Drawing.Size(155, 41);
        txtItemNumberSelected.TabIndex = 3;
        txtItemNumberSelected.KeyUp += new KeyEventHandler(txtItemNumberKeyUp);

        // Label: Receipt Number
        lblReceiptNumber = new Label();
        lblReceiptNumber.AutoSize = true;
        lblReceiptNumber.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblReceiptNumber.Location = new Point(1081, 22);
        lblReceiptNumber.TabIndex = 5;
        lblReceiptNumber.Text = "Receipt #:";
        Controls.Add(lblReceiptNumber);

        // Text Box: Receipt Number
        txtReceiptNumber = new TextBox();
        txtReceiptNumber.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtReceiptNumber.Location = new Point(1260, 18);
        txtReceiptNumber.Size = new System.Drawing.Size(105, 41);
        txtReceiptNumber.TabIndex = 6;
        txtReceiptNumber.Text = "000000";
        Controls.Add(txtReceiptNumber);

        // Column: umn: Item Number
        colItemNumber = new ColumnHeader();
        colItemNumber.Text = "Item #";
        colItemNumber.Width = 100;

        // Column: umn: Item Name
        colItemName = new ColumnHeader();
        colItemName.Text = "Item Name/Description";
        colItemName.Width = 610;

        // Column: umn: Item Size
        colItemSize = new ColumnHeader();
        colItemSize.Text = "Size";
        colItemSize.Width = 150;

        // Column: umn: Unit Price
        colUnitPrice = new ColumnHeader();
        colUnitPrice.Text = "Unit Price";
        colUnitPrice.TextAlign = HorizontalAlignment.Right;
        colUnitPrice.Width = 140;

        // Column: umn: Discount Rate
        colDiscountRate = new ColumnHeader();
        colDiscountRate.Text = "Dscnt Rt";
        colDiscountRate.TextAlign = HorizontalAlignment.Right;
        colDiscountRate.Width = 120;

        // Column: umn: Discount Amount
        colDiscountAmount = new ColumnHeader();
        colDiscountAmount.Text = "Dscnt Amt";
        colDiscountAmount.TextAlign = HorizontalAlignment.Right;
        colDiscountAmount.Width = 140;

        // Column: umn: Sale Price
        colSalePrice = new ColumnHeader();
        colSalePrice.Text = "Sale Price";
        colSalePrice.TextAlign = HorizontalAlignment.Right;
        colSalePrice.Width = 130;

        // List View: Selected Items
        lvwSoldItems = new ListView();
        lvwSoldItems.Columns.AddRange(new ColumnHeader[]
        {
            colItemNumber, colItemName,	colItemSize, colUnitPrice,
            colDiscountRate, colDiscountAmount,	colSalePrice
        });
        lvwSoldItems.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lvwSoldItems.FullRowSelect = true;
        lvwSoldItems.GridLines = true;
        lvwSoldItems.Location = new Point(16, 71);
        lvwSoldItems.Size = new System.Drawing.Size(1424, 321);
        lvwSoldItems.TabIndex = 8;
        lvwSoldItems.View = View.Details;

        // Date/Time Picker: Sale Date
        dtpSaleDate = new DateTimePicker();
        dtpSaleDate.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        dtpSaleDate.Location = new Point(16, 469);
        dtpSaleDate.Size = new System.Drawing.Size(402, 39);
        dtpSaleDate.TabIndex = 9;

        lblSaleTime = new Label();
        lblSaleTime.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblSaleTime.Location = new Point(429, 469);
        lblSaleTime.Text = "Sale Time";
        lblSaleTime.Size = new System.Drawing.Size(177, 39);
        lblSaleTime.TabIndex = 11;

        // Label: Tendered
        lblTendered = new Label();
        lblTendered.AutoSize = true;
        lblTendered.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblTendered.Location = new Point(1089, 449);
        lblTendered.TabIndex = 15;
        lblTendered.Text = "Tendered:";

        // Text Box: Amount Tendered
        txtAmountTendered = new TextBox();
        txtAmountTendered.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtAmountTendered.Location = new Point(1278, 445);
        txtAmountTendered.Size = new System.Drawing.Size(130, 41);
        txtAmountTendered.TabIndex = 14;
        txtAmountTendered.Text = "0.00";
        txtAmountTendered.TextAlign = HorizontalAlignment.Right;
        txtAmountTendered.KeyUp += new KeyEventHandler(txtAmountTenderedKeyUp);
        txtAmountTendered.Leave += new EventHandler(txtAmountTenderedLeave);

        // Label: Item Number to Remove
        lblItemNumberToRemove = new Label();
        lblItemNumberToRemove.AutoSize = true;
        lblItemNumberToRemove.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblItemNumberToRemove.Location = new Point(16, 416);
        lblItemNumberToRemove.TabIndex = 18;
        lblItemNumberToRemove.Text = "Item # to Remove:";

        // Text Box: Item Number to Remove
        txtItemNumberRemove = new TextBox();
        txtItemNumberRemove.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtItemNumberRemove.Location = new Point(290, 412);
        txtItemNumberRemove.Size = new System.Drawing.Size(155, 41);
        txtItemNumberRemove.TabIndex = 19;

        // Button: Remove Item
        btnRemoveItem = new Button();
        btnRemoveItem.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnRemoveItem.Location = new Point(451, 408);
        btnRemoveItem.Size = new System.Drawing.Size(155, 46);
        btnRemoveItem.TabIndex = 20;
        btnRemoveItem.Text = "Remove";
        btnRemoveItem.Click += new System.EventHandler(btnRemoveItemClick);

        // Label: Order Total
        lblOrderTotal = new Label();
        lblOrderTotal.AutoSize = true;
        lblOrderTotal.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblOrderTotal.Location = new Point(1089, 401);
        lblOrderTotal.TabIndex = 12;
        lblOrderTotal.Text = "Order Total:";
        txtEmployeeNumber = new TextBox();
        txtEmployeeName = new TextBox();
        btnSubmit = new Button();
        btnReset = new Button();
        btnClose = new Button();

        // Text Box: Order Total
        txtOrderTotal = new TextBox();
        txtOrderTotal.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtOrderTotal.Location = new Point(1278, 396);
        txtOrderTotal.Size = new System.Drawing.Size(130, 41);
        txtOrderTotal.TabIndex = 13;
        txtOrderTotal.Text = "0.00";
        txtOrderTotal.TextAlign = HorizontalAlignment.Right;

        // Label: Change
        lblChange = new Label();
        lblChange.AutoSize = true;
        lblChange.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblChange.Location = new Point(1089, 496);
        lblChange.TabIndex = 16;
        lblChange.Text = "Change:";

        // Text Box: Change
        txtChange = new TextBox();
        txtChange.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtChange.Location = new Point(1278, 492);
        txtChange.Size = new System.Drawing.Size(129, 41);
        txtChange.TabIndex = 17;
        txtChange.Text = "0.00";
        txtChange.TextAlign = HorizontalAlignment.Right;

        // Label: Employee Number
        lblEmployeeNumber = new Label();
        lblEmployeeNumber.AutoSize = true;
        lblEmployeeNumber.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblEmployeeNumber.Location = new Point(10, 558);
        lblEmployeeNumber.TabIndex = 0;
        lblEmployeeNumber.Text = "Employee #:";

        // Text Box: Employee Number
        txtEmployeeNumber.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtEmployeeNumber.Location = new Point(206, 554);
        txtEmployeeNumber.Size = new System.Drawing.Size(155, 41);
        txtEmployeeNumber.TabIndex = 1;
        txtEmployeeNumber.Leave += new System.EventHandler(txtEmployeeNumberLeave);

        // Text Box: Employee Name
        txtEmployeeName.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtEmployeeName.Location = new Point(370, 554);
        txtEmployeeName.Size = new System.Drawing.Size(499, 41);
        txtEmployeeName.TabIndex = 7;

        // Button: Reset
        btnReset.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnReset.Location = new Point(923, 551);
        btnReset.Size = new System.Drawing.Size(168, 46);
        btnReset.TabIndex = 10;
        btnReset.Text = "Reset";
        btnReset.Click += new System.EventHandler(btnResetClick);

        // Button: Submit
        btnSubmit.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnSubmit.Location = new Point(1097, 551);
        btnSubmit.Size = new System.Drawing.Size(177, 46);
        btnSubmit.TabIndex = 4;
        btnSubmit.Text = "Submit";
        btnSubmit.Click += new System.EventHandler(btnSubmitClick);

        // Button: Close
        btnClose.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnClose.Location = new Point(1281, 551);
        btnClose.Size = new System.Drawing.Size(129, 46);
        btnClose.TabIndex = 21;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);

        tmrDateTime = new Timer();
        tmrDateTime.Enabled = true;
        tmrDateTime.Tick += new EventHandler(tmrDateTimeTick);

        ClientSize = new System.Drawing.Size(1454, 611);
        Controls.Add(btnClose);
        Controls.Add(btnRemoveItem);
        Controls.Add(txtItemNumberRemove);
        Controls.Add(lblItemNumberToRemove);
        Controls.Add(btnReset);
        Controls.Add(btnSubmit);
        Controls.Add(txtEmployeeName);
        Controls.Add(txtOrderTotal);
        Controls.Add(lblOrderTotal);
        Controls.Add(txtChange);
        Controls.Add(lblChange);
        Controls.Add(txtAmountTendered);
        Controls.Add(lblTendered);
        Controls.Add(lblSaleTime);
        Controls.Add(dtpSaleDate);
        Controls.Add(txtEmployeeNumber);
        Controls.Add(lblEmployeeNumber);
        Controls.Add(lvwSoldItems);
        Controls.Add(txtItemNumberSelected);
        Controls.Add(lblItemNumberSelected);
        MaximizeBox = false;
        MinimizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "Fun Department Store - New Shopping Session";
        Load += new System.EventHandler(ShoppingSessionLoad);
    }

    private void txtItemNumberKeyUp(object sender, KeyEventArgs e)
    {
        bool itemFound = false;
        double dblTotal = 0.00;
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        if (e.KeyCode == Keys.Enter)
        {
            if (string.IsNullOrEmpty(txtItemNumberSelected.Text))
            {
                MessageBox.Show("You must enter an item number.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (File.Exists(strStoreItemsFile))
                {
                    using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
                    {
                        xdStoreItems.Load(fsStoreItems);
                        string itemNumber, itemName, itemSize, strDiscountRate;
                        double unitPrice, discountRate, discountAmount, salePrice;

                        XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                        foreach (XmlNode xnStoreItem in xnlStoreItems)
                        {
                            if (xnStoreItem.InnerText == txtItemNumberSelected.Text)
                            {
                                itemFound = true;

                                itemNumber = xnStoreItem.InnerText;
                                itemName = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                                itemSize = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                                unitPrice = double.Parse(xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText);
                                strDiscountRate = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;

                                if ((string.IsNullOrEmpty(strDiscountRate)) || (double.Parse(strDiscountRate) <= 0.00))
                                {
                                    discountRate = 0.00;
                                    discountAmount = 0.00;
                                    salePrice = unitPrice;
                                }
                                else
                                {
                                    discountRate = double.Parse(strDiscountRate) / 100.00;
                                    discountAmount = unitPrice * discountRate;
                                    salePrice = unitPrice - discountAmount;
                                }

                                ListViewItem lviStoreItem = new ListViewItem(itemNumber); // Item Number
                                lviStoreItem.SubItems.Add(itemName); // Item Name
                                lviStoreItem.SubItems.Add(itemSize); // Item Size
                                lviStoreItem.SubItems.Add(unitPrice.ToString("F"));

                                if (discountRate == 0.00)
                                {
                                    lviStoreItem.SubItems.Add(""); // Discount Rate
                                    lviStoreItem.SubItems.Add(""); // Discount Amount
                                    lviStoreItem.SubItems.Add(unitPrice.ToString("F")); // Unit Price
                                }
                                else
                                {
                                    lviStoreItem.SubItems.Add((discountRate * 100).ToString() + "%");
                                    lviStoreItem.SubItems.Add(discountAmount.ToString("F"));
                                    lviStoreItem.SubItems.Add(salePrice.ToString("F"));
                                }

                                lvwSoldItems.Items.Add(lviStoreItem);
                            }
                        }

                        txtItemNumberSelected.Text = "";

                        if (itemFound == false)
                        {
                            MessageBox.Show("There is no item with that item number.",
                                            "FunDS - Fun Department Store",
                                            MessageBoxButtons.OK,
                                            MessageBoxIcon.Information);
                        }
                    }

                    if (lvwSoldItems.Items.Count > 0)
                    {
                        foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
                            dblTotal += double.Parse(lviStoreItem.SubItems[6].Text);

                        txtOrderTotal.Text = dblTotal.ToString("F");
                    }
                }
            }
        }
    }

    private void ShoppingSessionLoad(object sender, EventArgs e)
    {
        btnResetClick(sender, e);
    }

    private void txtEmployeeNumberLeave(object sender, EventArgs e)
    {
        bool employeeFound = false;
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        if (string.IsNullOrEmpty(txtEmployeeNumber.Text))
        {
            return;
        }
        else
        {
            if (File.Exists(strEmployeesFile))
            {
                using (FileStream fsEmployees = new FileStream(strEmployeesFile, FileMode.Open, FileAccess.Read))
                {
                    xdEmployees.Load(fsEmployees);

                    XmlNodeList xnlEmployees = xdEmployees.GetElementsByTagName("EmployeeNumber");

                    foreach (XmlNode xnEmployee in xnlEmployees)
                    {
                        if (txtEmployeeNumber.Text == xnEmployee.InnerText)
                        {
                            employeeFound = true;
                            txtEmployeeName.Text = string.Concat(xnEmployee.NextSibling.NextSibling.InnerText, ", ", xnEmployee.NextSibling.InnerText);
                        }
                    }

                    if (employeeFound == false)
                    {
                        MessageBox.Show("There is no employee with that number.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                    }
                }
            }
        }
    }

    private void txtAmountTenderedKeyUp(object sender, KeyEventArgs e)
    {
        double orderTotal = 0.00;
        double amountTendered = 0.00;
        double change = 0.00;

        if ((e.KeyCode == Keys.Tab) || (e.KeyCode == Keys.Enter))
        {
            if (string.IsNullOrEmpty(txtOrderTotal.Text))
            {
                return;
            }
            else if (string.IsNullOrEmpty(txtAmountTendered.Text))
            {
                return;
            }
            else
            {
                orderTotal = double.Parse(txtOrderTotal.Text);
                amountTendered = double.Parse(txtAmountTendered.Text);
                change = amountTendered - orderTotal;

                txtChange.Text = change.ToString("F");
            }
        }
    }

    private void txtAmountTenderedLeave(object sender, EventArgs e)
    {
        double orderTotal = 0.00;
        double amountTendered = 0.00;
        double change = 0.00;

        if (string.IsNullOrEmpty(txtOrderTotal.Text))
        {
            return;
        }
        else if (string.IsNullOrEmpty(txtAmountTendered.Text))
        {
            return;
        }
        else
        {
            orderTotal = double.Parse(txtOrderTotal.Text);
            amountTendered = double.Parse(txtAmountTendered.Text);
            change = amountTendered - orderTotal;

            txtChange.Text = change.ToString("F");
        }
    }

    private void btnRemoveItemClick(object sender, EventArgs e)
    {
        double dblTotal = 0.00;
        bool itemFound = false;

        if (lvwSoldItems.Items.Count == 0)
        {
            MessageBox.Show("The list view is empty.",
                            "FunDS", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
        else if (string.IsNullOrEmpty(txtItemNumberRemove.Text))
        {
            MessageBox.Show("You must enter an item number and that exists in the list view.",
                            "FunDS", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
        else
        {
            foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
            {
                if (lviStoreItem.SubItems[0].Text.Equals(txtItemNumberRemove.Text))
                {
                    itemFound = true;
                    lvwSoldItems.Items.Remove(lviStoreItem);
                }
            }

            if (itemFound == false)
            {
                MessageBox.Show("That item number is not in the list view.",
                                "FunDS", MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }

            if (lvwSoldItems.Items.Count > 0)
            {
                foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
                    dblTotal += double.Parse(lviStoreItem.SubItems[6].Text);

                txtOrderTotal.Text = dblTotal.ToString("F");
                txtAmountTendered.Text = "0.00";
                txtChange.Text = "0.00";
            }
            else
            {
                txtOrderTotal.Text = "0.00";
                txtAmountTendered.Text = "0.00";
                txtChange.Text = "0.00";
            }

            txtItemNumberRemove.Text = "";
        }
    }

    private void btnResetClick(object sender, EventArgs e)
    {
        int iReceiptNumber = 100000;
        XmlDocument xdStoreSales = new XmlDocument();
        string strStoreSalesFile = @"C:\Fun Department Store\StoreSales.xml";

        if (File.Exists(strStoreSalesFile))
        {
            using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreSales.Load(fsStoreSales);

                XmlNodeList xnlStoreSales = xdStoreSales.GetElementsByTagName("ReceiptNumber");

                foreach (XmlNode xnStoreSale in xnlStoreSales)
                {
                    iReceiptNumber = int.Parse(xnStoreSale.InnerText);
                }
            }
        }

        txtReceiptNumber.Text = (iReceiptNumber + 1).ToString();
        txtItemNumberSelected.Text = "";
        lvwSoldItems.Items.Clear();
        txtItemNumberRemove.Text = "";
        dtpSaleDate.Value = DateTime.Now;
        lblSaleTime.Text = DateTime.Now.ToString();
        txtEmployeeNumber.Text = ""; ;
        txtEmployeeName.Text = "";
        txtOrderTotal.Text = "0.00";
        txtAmountTendered.Text = "0.00";
        txtChange.Text = "0.00";
    }

    private void btnSubmitClick(object sender, EventArgs e)
    {
        int iSoldItemID = 0;
        XmlDocument xdSoldItems = new XmlDocument();
        XmlDocument xdStoreSales = new XmlDocument();
        XmlDocument xdStoreItems = new XmlDocument();
        string strSoldItemsFile = @"C:\Fun Department Store\SoldItems.xml";
        string strStoreSalesFile = @"C:\Fun Department Store\StoreSales.xml";
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems1.xml";

        if (lvwSoldItems.Items.Count == 0)
        {
            MessageBox.Show("There is no customer order to save.",
                            "FunDS", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }

        if (!File.Exists(strStoreSalesFile))
        {
            using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Create, FileAccess.Write))
            {
                xdStoreSales.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                                     "<StoreSales></StoreSales>");
                xdStoreSales.Save(fsStoreSales);
            }
        }

        using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Open, FileAccess.Read))
        {
            xdStoreSales.Load(fsStoreSales);
        }

        using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Create, FileAccess.Write))
        {
            XmlElement xeStoreSale = xdStoreSales.CreateElement("StoreSale");
            xeStoreSale.InnerXml = "<ReceiptNumber>" + txtReceiptNumber.Text + "</ReceiptNumber>" +
                                   "<EmployeeNumber>" + txtEmployeeNumber.Text + "</EmployeeNumber>" +
                                   "<SaleDate>" + dtpSaleDate.Value.ToShortDateString() + "</SaleDate>" +
                                   "<SaleTime>" + lblSaleTime.Text + "</SaleTime>" +
                                   "<OrderTotal>" + txtOrderTotal.Text + "</OrderTotal>" +
                                   "<AmountTendered>" + txtAmountTendered.Text + "</AmountTendered>" +
                                   "<Change>" + txtChange.Text + "</Change>";
            xdStoreSales.DocumentElement.AppendChild(xeStoreSale);

            xdStoreSales.Save(fsStoreSales);
        }

        if (!File.Exists(strSoldItemsFile))
        {
            using (FileStream fsSoldItems = new FileStream(strSoldItemsFile, FileMode.Create, FileAccess.Write))
            {
                xdSoldItems.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                                    "<SoldItems></SoldItems>");
                xdSoldItems.Save(fsSoldItems);
            }
        }

        using (FileStream fsSoldItems = new FileStream(strSoldItemsFile, FileMode.Open, FileAccess.Read))
        {
            xdSoldItems.Load(fsSoldItems);
            XmlNodeList xnlSoldItems = xdSoldItems.GetElementsByTagName("SoldItemID");

            foreach (XmlNode xnSoldItem in xnlSoldItems)
                iSoldItemID = int.Parse(xnSoldItem.InnerText);
        }

        iSoldItemID = iSoldItemID + 1;

        using (FileStream fsSoldItems = new FileStream(strSoldItemsFile, FileMode.Create, FileAccess.Write))
        {
            foreach (ListViewItem lviSoldItem in lvwSoldItems.Items)
            {
                XmlElement xeSoldItem = xdSoldItems.CreateElement("SoldItem");
                xeSoldItem.InnerXml = "<SoldItemID>" + iSoldItemID.ToString() + "</SoldItemID>" +
                                      "<ReceiptNumber>" + txtReceiptNumber.Text + "</ReceiptNumber>" +
                                      "<ItemNumber>" + lviSoldItem.SubItems[0].Text + "</ItemNumber>" +
                                      "<ItemName>" + lviSoldItem.SubItems[1].Text + "</ItemName>" +
                                      "<ItemSize>" + lviSoldItem.SubItems[2].Text + "</ItemSize>" +
                                      "<UnitPrice>" + lviSoldItem.SubItems[3].Text + "</UnitPrice>" +
                                      "<DiscountRate>" + lviSoldItem.SubItems[4].Text + "</DiscountRate>" +
                                      "<DiscountAmount>" + lviSoldItem.SubItems[5].Text + "</DiscountAmount>" +
                                      "<SalePrice>" + lviSoldItem.SubItems[6].Text + "</SalePrice>";
                xdSoldItems.DocumentElement.AppendChild(xeSoldItem);
                iSoldItemID++;
            }

            xdSoldItems.Save(fsSoldItems);

            MessageBox.Show("The customer's order has been saved.",
                            "FunDS", MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
        }

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                // Remove the items of the list view from the StoreItems table
                foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
                {
                    foreach (XmlNode xnStoreItem in xnlStoreItems)
                    {
                        if (xnStoreItem.InnerText == lviStoreItem.SubItems[0].Text)
                            xdStoreItems.DocumentElement.RemoveChild(xnStoreItem.ParentNode);
                    }
                }
            }

            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Create, FileAccess.Write))
            {
                xdStoreItems.Save(fsStoreItems);
            }
        }

        btnResetClick(sender, e);
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }

    private void tmrDateTimeTick(object sender, EventArgs e)
    {
        dtpSaleDate.Value = DateTime.Today;
        lblSaleTime.Text = DateTime.Now.ToLongTimeString();
    }
}

On the main menu, click File -> New
When asked whether you want to save, click Save
In the top combo box, make sure the FunDS1 folder is displaying, Set the Save As Type to All Files
Set the File Name to PointOfSale.cs
Click Save

Reviewing a Shopping Session

Some time to time, the company management must review store sales. Also, a customer may come with a complaint about anything. The first thing to do is to review a customer order. To handle this, we will create a form in which a user can enter a receipt number and click a button to locate its record. If the purchase is found, the form will display (that's all we will do at this time; otherwise, there are many actions that can be taken such as deleting an items from the receipt (and re-imbursing the customer) and putting the information about the returned item to another list, etc).

Practical Learning: Reviewing a Shopping Session

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;

public class ShoppingSessionReview : Form
{
    private Label lblItemNumberSelected;
    private TextBox txtItemNumberSelected;
    private Label lblReceiptNumber;
    private TextBox txtReceiptNumber;
    private Button btnFind;
    private ColumnHeader colItemNumber;
    private ColumnHeader colItemName;
    private ColumnHeader colItemSize;
    private ColumnHeader colUnitPrice;
    private ColumnHeader colDiscountRate;
    private ColumnHeader colDiscountAmount;
    private ColumnHeader colSalePrice;
    private ListView lvwSoldItems;

    private TextBox txtEmployeeNumber;
    private Label lblEmployeeNumber;
    private DateTimePicker dtpSaleDate;
    private Label lblSaleTime;
    private TextBox txtAmountTendered;
    private Label lblTendered;
    private TextBox txtChange;
    private Label lblChange;
    private TextBox txtOrderTotal;
    private Label lblOrderTotal;
    private TextBox txtEmployeeName;
    private Button btnSubmit;
    private TextBox txtItemNumberRemove;
    private Label lblItemNumberToRemove;
    private Button btnRemoveItem;
    private Button btnClose;

    private Timer tmrDateTime;

    public ShoppingSessionReview()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Label: Item Number to Add
        lblItemNumberSelected = new Label();
        lblItemNumberSelected.AutoSize = true;
        lblItemNumberSelected.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblItemNumberSelected.Location = new Point(16, 22);
        lblItemNumberSelected.TabIndex = 20;
        lblItemNumberSelected.Text = "Item # to Add:";

        // Text Box: Item Number to Add
        txtItemNumberSelected = new TextBox();
        txtItemNumberSelected.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtItemNumberSelected.Location = new Point(235, 18);
        txtItemNumberSelected.Size = new System.Drawing.Size(155, 41);
        txtItemNumberSelected.TabIndex = 21;
        txtItemNumberSelected.KeyUp += new KeyEventHandler(txtItemNumberKeyUp);

        // Label: Receipt Number
        lblReceiptNumber = new Label();
        lblReceiptNumber.AutoSize = true;
        lblReceiptNumber.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblReceiptNumber.Location = new Point(881, 22);
        lblReceiptNumber.TabIndex = 0;
        lblReceiptNumber.Text = "Receipt #:";

        // Text Box: Receipt Number
        txtReceiptNumber = new TextBox();
        txtReceiptNumber.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtReceiptNumber.Location = new Point(1060, 18);
        txtReceiptNumber.Size = new System.Drawing.Size(105, 41);
        txtReceiptNumber.TabIndex = 1;

        // Button: Find
        btnFind = new Button();
        btnFind.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnFind.Location = new Point(1178, 16);
        btnFind.Size = new System.Drawing.Size(168, 46);
        btnFind.TabIndex = 2;
        btnFind.Text = "Find";
        btnFind.Click += new System.EventHandler(btnFindClick);
        Controls.Add(btnFind);

        // Column: umn: Item Number
        colItemNumber = new ColumnHeader();
        colItemNumber.Text = "Item #";
        colItemNumber.Width = 100;

        // Column: umn: Item Name
        colItemName = new ColumnHeader();
        colItemName.Text = "Item Name/Description";
        colItemName.Width = 610;

        // Column: umn: Item Size
        colItemSize = new ColumnHeader();
        colItemSize.Text = "Size";
        colItemSize.Width = 150;

        // Column: umn: Unit Price
        colUnitPrice = new ColumnHeader();
        colUnitPrice.Text = "Unit Price";
        colUnitPrice.TextAlign = HorizontalAlignment.Right;
        colUnitPrice.Width = 140;

        // Column: umn: Discount Rate
        colDiscountRate = new ColumnHeader();
        colDiscountRate.Text = "Dscnt Rt";
        colDiscountRate.TextAlign = HorizontalAlignment.Right;
        colDiscountRate.Width = 120;

        // Column: umn: Discount Amount
        colDiscountAmount = new ColumnHeader();
        colDiscountAmount.Text = "Dscnt Amt";
        colDiscountAmount.TextAlign = HorizontalAlignment.Right;
        colDiscountAmount.Width = 140;

        // Column: umn: Sale Price
        colSalePrice = new ColumnHeader();
        colSalePrice.Text = "Sale Price";
        colSalePrice.TextAlign = HorizontalAlignment.Right;
        colSalePrice.Width = 130;

        // List View: Selected Items
        lvwSoldItems = new ListView();
        lvwSoldItems.Columns.AddRange(new ColumnHeader[]
        {
            colItemNumber, colItemName,	colItemSize, colUnitPrice,
            colDiscountRate, colDiscountAmount,	colSalePrice
        });
        lvwSoldItems.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lvwSoldItems.FullRowSelect = true;
        lvwSoldItems.GridLines = true;
        lvwSoldItems.Location = new Point(16, 71);
        lvwSoldItems.Size = new System.Drawing.Size(1424, 321);
        lvwSoldItems.TabIndex = 8;
        lvwSoldItems.View = View.Details;

        // Date/Time Picker: Sale Date
        dtpSaleDate = new DateTimePicker();
        dtpSaleDate.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        dtpSaleDate.Location = new Point(16, 469);
        dtpSaleDate.Size = new System.Drawing.Size(402, 39);
        dtpSaleDate.TabIndex = 9;

        lblSaleTime = new Label();
        lblSaleTime.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblSaleTime.Location = new Point(429, 469);
        lblSaleTime.Text = "Sale Time";
        lblSaleTime.Size = new System.Drawing.Size(177, 39);
        lblSaleTime.TabIndex = 11;

        // Label: Tendered
        lblTendered = new Label();
        lblTendered.AutoSize = true;
        lblTendered.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblTendered.Location = new Point(1089, 449);
        lblTendered.TabIndex = 15;
        lblTendered.Text = "Tendered:";

        // Text Box: Amount Tendered
        txtAmountTendered = new TextBox();
        txtAmountTendered.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtAmountTendered.Location = new Point(1278, 445);
        txtAmountTendered.Size = new System.Drawing.Size(130, 41);
        txtAmountTendered.TabIndex = 14;
        txtAmountTendered.Text = "0.00";
        txtAmountTendered.TextAlign = HorizontalAlignment.Right;
        txtAmountTendered.KeyUp += new KeyEventHandler(txtAmountTenderedKeyUp);
        txtAmountTendered.Leave += new EventHandler(txtAmountTenderedLeave);

        // Label: Item Number to Remove
        lblItemNumberToRemove = new Label();
        lblItemNumberToRemove.AutoSize = true;
        lblItemNumberToRemove.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblItemNumberToRemove.Location = new Point(16, 416);
        lblItemNumberToRemove.TabIndex = 18;
        lblItemNumberToRemove.Text = "Item # to Remove:";

        // Text Box: Item Number to Remove
        txtItemNumberRemove = new TextBox();
        txtItemNumberRemove.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtItemNumberRemove.Location = new Point(290, 412);
        txtItemNumberRemove.Size = new System.Drawing.Size(155, 41);
        txtItemNumberRemove.TabIndex = 19;

        // Button: Remove Item
        btnRemoveItem = new Button();
        btnRemoveItem.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnRemoveItem.Location = new Point(451, 408);
        btnRemoveItem.Size = new System.Drawing.Size(155, 46);
        btnRemoveItem.TabIndex = 20;
        btnRemoveItem.Text = "Remove";
        btnRemoveItem.Click += new System.EventHandler(btnRemoveItemClick);

        // Label: Order Total
        lblOrderTotal = new Label();
        lblOrderTotal.AutoSize = true;
        lblOrderTotal.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblOrderTotal.Location = new Point(1089, 401);
        lblOrderTotal.TabIndex = 12;
        lblOrderTotal.Text = "Order Total:";

        // Text Box: Order Total
        txtOrderTotal = new TextBox();
        txtOrderTotal.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtOrderTotal.Location = new Point(1278, 396);
        txtOrderTotal.Size = new System.Drawing.Size(130, 41);
        txtOrderTotal.TabIndex = 13;
        txtOrderTotal.Text = "0.00";
        txtOrderTotal.TextAlign = HorizontalAlignment.Right;

        // Label: Change
        lblChange = new Label();
        lblChange.AutoSize = true;
        lblChange.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblChange.Location = new Point(1089, 496);
        lblChange.TabIndex = 16;
        lblChange.Text = "Change:";

        // Text Box: Change
        txtChange = new TextBox();
        txtChange.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtChange.Location = new Point(1278, 492);
        txtChange.Size = new System.Drawing.Size(129, 41);
        txtChange.TabIndex = 17;
        txtChange.Text = "0.00";
        txtChange.TextAlign = HorizontalAlignment.Right;

        // Label: Employee Number
        lblEmployeeNumber = new Label();
        lblEmployeeNumber.AutoSize = true;
        lblEmployeeNumber.Font = new System.Drawing.Font("Georgia", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        lblEmployeeNumber.Location = new Point(10, 558);
        lblEmployeeNumber.TabIndex = 0;
        lblEmployeeNumber.Text = "Employee #:";

        // Text Box: Employee Number
        txtEmployeeNumber = new TextBox();
        txtEmployeeNumber.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtEmployeeNumber.Location = new Point(206, 554);
        txtEmployeeNumber.Size = new System.Drawing.Size(155, 41);
        txtEmployeeNumber.TabIndex = 1;
        txtEmployeeNumber.Leave += new System.EventHandler(txtEmployeeNumberLeave);

        // Text Box: Employee Name
        txtEmployeeName = new TextBox();
        txtEmployeeName.Font = new System.Drawing.Font("Times New Roman", 21.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        txtEmployeeName.Location = new Point(370, 554);
        txtEmployeeName.Size = new System.Drawing.Size(499, 41);
        txtEmployeeName.TabIndex = 7;

        // Button: Submit
        btnSubmit = new Button();
        btnSubmit.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnSubmit.Location = new Point(1097, 551);
        btnSubmit.Size = new System.Drawing.Size(177, 46);
        btnSubmit.TabIndex = 3;
        btnSubmit.Text = "Submit";
        btnSubmit.Click += new System.EventHandler(btnSubmitClick);
        Controls.Add(btnSubmit);

        // Button: Close
        btnClose = new Button();
        btnClose.Font = new System.Drawing.Font("Times New Roman", 20.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnClose.Location = new Point(1281, 551);
        btnClose.Size = new System.Drawing.Size(129, 46);
        btnClose.TabIndex = 4;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);
        Controls.Add(btnClose);

        tmrDateTime = new Timer();
        tmrDateTime.Enabled = false;
        tmrDateTime.Tick += new EventHandler(tmrDateTimeTick);

        ClientSize = new System.Drawing.Size(1454, 611);
        Controls.Add(txtItemNumberSelected);
        Controls.Add(lblItemNumberSelected);
        Controls.Add(txtReceiptNumber);
        Controls.Add(lblReceiptNumber);
        Controls.Add(btnRemoveItem);
        Controls.Add(txtItemNumberRemove);
        Controls.Add(lblItemNumberToRemove);
        Controls.Add(txtEmployeeName);
        Controls.Add(txtOrderTotal);
        Controls.Add(lblOrderTotal);
        Controls.Add(txtChange);
        Controls.Add(lblChange);
        Controls.Add(txtAmountTendered);
        Controls.Add(lblTendered);
        Controls.Add(lblSaleTime);
        Controls.Add(dtpSaleDate);
        Controls.Add(txtEmployeeNumber);
        Controls.Add(lblEmployeeNumber);
        Controls.Add(lvwSoldItems);
        MaximizeBox = false;
        MinimizeBox = false;
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - Shopping Session";
        Load += new System.EventHandler(ShoppingSessionLoad);
    }

    private void btnFindClick(object sender, EventArgs e)
    {
        bool receiptFound = false;
        XmlDocument xdSoldItems = new XmlDocument();
        XmlDocument xdStoreSales = new XmlDocument();
        string strSoldItemsFile = @"C:\Fun Department Store\SoldItems.xml";
        string strStoreSalesFile = @"C:\Fun Department Store\StoreSales.xml";

        if (string.IsNullOrEmpty(txtReceiptNumber.Text))
        {
            MessageBox.Show("You must enter a receipt number.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }

        if (File.Exists(strStoreSalesFile))
        {
            using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreSales.Load(fsStoreSales);

                XmlNodeList xnlStoreSales = xdStoreSales.GetElementsByTagName("ReceiptNumber");

                foreach (XmlNode xnStoreSale in xnlStoreSales)
                {
                    if (xnStoreSale.InnerText == txtReceiptNumber.Text)
                    {
                        receiptFound = true;

                        txtEmployeeNumber.Text = xnStoreSale.NextSibling.InnerText;
                        dtpSaleDate.Value = DateTime.Parse(xnStoreSale.NextSibling.NextSibling.InnerText);
                        lblSaleTime.Text = xnStoreSale.NextSibling.NextSibling.NextSibling.InnerText;
                        txtOrderTotal.Text = xnStoreSale.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtAmountTendered.Text = xnStoreSale.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                        txtChange.Text = xnStoreSale.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;

                        txtEmployeeNumberLeave(sender, e);
                    }
                }
            }
        }

        if (File.Exists(strSoldItemsFile))
        {
            using (FileStream fsSoldItems = new FileStream(strSoldItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdSoldItems.Load(fsSoldItems);
                XmlNodeList xnlSoldItems = xdSoldItems.GetElementsByTagName("ReceiptNumber");

                lvwSoldItems.Items.Clear();

                foreach (XmlNode xnSoldItem in xnlSoldItems)
                {
                    if (xnSoldItem.InnerText == txtReceiptNumber.Text)
                    {
                        ListViewItem lviStoreItem = new ListViewItem(xnSoldItem.NextSibling.InnerText); // Item Number
                        lviStoreItem.SubItems.Add(xnSoldItem.NextSibling.NextSibling.InnerText); // Item Name
                        lviStoreItem.SubItems.Add(xnSoldItem.NextSibling.NextSibling.NextSibling.InnerText); // Item Size
                        lviStoreItem.SubItems.Add(xnSoldItem.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // Unit Price
                        lviStoreItem.SubItems.Add(xnSoldItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // Discount Rate
                        lviStoreItem.SubItems.Add(xnSoldItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // Discount Amount
                        lviStoreItem.SubItems.Add(xnSoldItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText); // Sale Price

                        lvwSoldItems.Items.Add(lviStoreItem);
                    }
                }
            }
        }

        if (receiptFound == false)
        {
            MessageBox.Show("There is no sale order with that receipt number.",
                            "FunDS - Fun Department Store",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
            return;
        }
    }

    private void ResetForm()
    {
        txtReceiptNumber.Text = "";
        txtItemNumberSelected.Text = "";
        lvwSoldItems.Items.Clear();
        txtItemNumberRemove.Text = "";
        dtpSaleDate.Value = DateTime.Now;
        lblSaleTime.Text = DateTime.Now.ToString();
        txtEmployeeNumber.Text = ""; ;
        txtEmployeeName.Text = "";
        txtOrderTotal.Text = "0.00";
        txtAmountTendered.Text = "0.00";
        txtChange.Text = "0.00";
    }

    private void txtItemNumberKeyUp(object sender, KeyEventArgs e)
    {
        bool itemFound = false;
        double dblTotal = 0.00;
        XmlDocument xdStoreItems = new XmlDocument();
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        if (e.KeyCode == Keys.Enter)
        {
            if (string.IsNullOrEmpty(txtItemNumberSelected.Text))
            {
                MessageBox.Show("You must enter an item number.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }
            else
            {
                if (File.Exists(strStoreItemsFile))
                {
                    using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
                    {
                        xdStoreItems.Load(fsStoreItems);
                        string itemNumber, itemName, itemSize, strDiscountRate;
                        double unitPrice, discountRate, discountAmount, salePrice;

                        XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                        foreach (XmlNode xnStoreItem in xnlStoreItems)
                        {
                            if (xnStoreItem.InnerText == txtItemNumberSelected.Text)
                            {
                                itemFound = true;

                                itemNumber = xnStoreItem.InnerText;
                                itemName = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                                itemSize = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;
                                unitPrice = double.Parse(xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText);
                                strDiscountRate = xnStoreItem.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.NextSibling.InnerText;

                                if ((string.IsNullOrEmpty(strDiscountRate)) || (double.Parse(strDiscountRate) <= 0.00))
                                {
                                    discountRate = 0.00;
                                    discountAmount = 0.00;
                                    salePrice = unitPrice;
                                }
                                else
                                {
                                    discountRate = double.Parse(strDiscountRate) / 100.00;
                                    discountAmount = unitPrice * discountRate;
                                    salePrice = unitPrice - discountAmount;
                                }

                                ListViewItem lviStoreItem = new ListViewItem(itemNumber); // Item Number
                                lviStoreItem.SubItems.Add(itemName); // Item Name
                                lviStoreItem.SubItems.Add(itemSize); // Item Size
                                lviStoreItem.SubItems.Add(unitPrice.ToString("F"));

                                if (discountRate == 0.00)
                                {
                                    lviStoreItem.SubItems.Add(""); // Discount Rate
                                    lviStoreItem.SubItems.Add(""); // Discount Amount
                                    lviStoreItem.SubItems.Add(unitPrice.ToString("F")); // Unit Price
                                }
                                else
                                {
                                    lviStoreItem.SubItems.Add((discountRate * 100).ToString() + "%");
                                    lviStoreItem.SubItems.Add(discountAmount.ToString("F"));
                                    lviStoreItem.SubItems.Add(salePrice.ToString("F"));
                                }

                                lvwSoldItems.Items.Add(lviStoreItem);
                            }
                        }

                        txtItemNumberSelected.Text = "";

                        if (itemFound == false)
                        {
                            MessageBox.Show("There is no item with that item number.",
                                            "FunDS - Fun Department Store",
                                            MessageBoxButtons.OK,
                                            MessageBoxIcon.Information);
                        }
                    }

                    if (lvwSoldItems.Items.Count > 0)
                    {
                        foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
                            dblTotal += double.Parse(lviStoreItem.SubItems[6].Text);

                        txtOrderTotal.Text = dblTotal.ToString("F");
                    }
                }
            }
        }
    }

    private void ShoppingSessionLoad(object sender, EventArgs e)
    {
    }

    private void txtEmployeeNumberLeave(object sender, EventArgs e)
    {
        bool employeeFound = false;
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        if (string.IsNullOrEmpty(txtEmployeeNumber.Text))
        {
            return;
        }
        else
        {
            if (File.Exists(strEmployeesFile))
            {
                using (FileStream fsEmployees = new FileStream(strEmployeesFile, FileMode.Open, FileAccess.Read))
                {
                    xdEmployees.Load(fsEmployees);

                    XmlNodeList xnlEmployees = xdEmployees.GetElementsByTagName("EmployeeNumber");

                    foreach (XmlNode xnEmployee in xnlEmployees)
                    {
                        if (txtEmployeeNumber.Text == xnEmployee.InnerText)
                        {
                            employeeFound = true;
                            txtEmployeeName.Text = string.Concat(xnEmployee.NextSibling.NextSibling.InnerText, ", ", xnEmployee.NextSibling.InnerText);
                        }
                    }

                    if (employeeFound == false)
                    {
                        MessageBox.Show("There is no employee with that number.",
                                "FunDS - Fun Department Store",
                                MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                    }
                }
            }
        }
    }

    private void txtAmountTenderedKeyUp(object sender, KeyEventArgs e)
    {
        double orderTotal = 0.00;
        double amountTendered = 0.00;
        double change = 0.00;

        if ((e.KeyCode == Keys.Tab) || (e.KeyCode == Keys.Enter))
        {
            if (string.IsNullOrEmpty(txtOrderTotal.Text))
            {
                return;
            }
            else if (string.IsNullOrEmpty(txtAmountTendered.Text))
            {
                return;
            }
            else
            {
                orderTotal = double.Parse(txtOrderTotal.Text);
                amountTendered = double.Parse(txtAmountTendered.Text);
                change = amountTendered - orderTotal;

                txtChange.Text = change.ToString("F");
            }
        }
    }

    private void txtAmountTenderedLeave(object sender, EventArgs e)
    {
        double orderTotal = 0.00;
        double amountTendered = 0.00;
        double change = 0.00;

        if (string.IsNullOrEmpty(txtOrderTotal.Text))
        {
            return;
        }
        else if (string.IsNullOrEmpty(txtAmountTendered.Text))
        {
            return;
        }
        else
        {
            orderTotal = double.Parse(txtOrderTotal.Text);
            amountTendered = double.Parse(txtAmountTendered.Text);
            change = amountTendered - orderTotal;

            txtChange.Text = change.ToString("F");
        }
    }

    private void btnRemoveItemClick(object sender, EventArgs e)
    {
        double dblTotal = 0.00;
        bool itemFound = false;

        if (lvwSoldItems.Items.Count == 0)
        {
            MessageBox.Show("The list view is empty.",
                            "FunDS", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
        else if (string.IsNullOrEmpty(txtItemNumberRemove.Text))
        {
            MessageBox.Show("You must enter an item number and that exists in the list view.",
                            "FunDS", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }
        else
        {
            foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
            {
                if (lviStoreItem.SubItems[0].Text.Equals(txtItemNumberRemove.Text))
                {
                    itemFound = true;
                    lvwSoldItems.Items.Remove(lviStoreItem);
                }
            }

            if (itemFound == false)
            {
                MessageBox.Show("That item number is not in the list view.",
                                "FunDS", MessageBoxButtons.OK,
                                MessageBoxIcon.Information);
                return;
            }

            if (lvwSoldItems.Items.Count > 0)
            {
                foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
                    dblTotal += double.Parse(lviStoreItem.SubItems[6].Text);

                txtOrderTotal.Text = dblTotal.ToString("F");
                txtAmountTendered.Text = "0.00";
                txtChange.Text = "0.00";
            }
            else
            {
                txtOrderTotal.Text = "0.00";
                txtAmountTendered.Text = "0.00";
                txtChange.Text = "0.00";
            }

            txtItemNumberRemove.Text = "";
        }
    }

    private void btnSubmitClick(object sender, EventArgs e)
    {
        int iSoldItemID = 0;
        XmlDocument xdSoldItems = new XmlDocument();
        XmlDocument xdStoreSales = new XmlDocument();
        XmlDocument xdStoreItems = new XmlDocument();
        string strSoldItemsFile = @"C:\Fun Department Store\SoldItems.xml";
        string strStoreSalesFile = @"C:\Fun Department Store\StoreSales.xml";
        string strStoreItemsFile = @"C:\Fun Department Store\StoreItems.xml";

        if (lvwSoldItems.Items.Count == 0)
        {
            MessageBox.Show("There is no customer order to save.",
                            "FunDS", MessageBoxButtons.OK, MessageBoxIcon.Information);
            return;
        }

        if (!File.Exists(strStoreSalesFile))
        {
            using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Create, FileAccess.Write))
            {
                xdStoreSales.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                                     "<StoreSales></StoreSales>");
                xdStoreSales.Save(fsStoreSales);
            }
        }

        using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Open, FileAccess.Read))
        {
            xdStoreSales.Load(fsStoreSales);
        }

        using (FileStream fsStoreSales = new FileStream(strStoreSalesFile, FileMode.Create, FileAccess.Write))
        {
            XmlElement xeStoreSale = xdStoreSales.CreateElement("StoreSale");
            xeStoreSale.InnerXml = "<ReceiptNumber>" + txtReceiptNumber.Text + "</ReceiptNumber>" +
                                   "<EmployeeNumber>" + txtEmployeeNumber.Text + "</EmployeeNumber>" +
                                   "<SaleDate>" + dtpSaleDate.Value.ToShortDateString() + "</SaleDate>" +
                                   "<SaleTime>" + lblSaleTime.Text + "</SaleTime>" +
                                   "<OrderTotal>" + txtOrderTotal.Text + "</OrderTotal>" +
                                   "<AmountTendered>" + txtAmountTendered.Text + "</AmountTendered>" +
                                   "<Change>" + txtChange.Text + "</Change>";
            xdStoreSales.DocumentElement.AppendChild(xeStoreSale);

            xdStoreSales.Save(fsStoreSales);
        }

        if (!File.Exists(strSoldItemsFile))
        {
            using (FileStream fsSoldItems = new FileStream(strSoldItemsFile, FileMode.Create, FileAccess.Write))
            {
                xdSoldItems.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                                    "<SoldItems></SoldItems>");
                xdSoldItems.Save(fsSoldItems);
            }
        }

        using (FileStream fsSoldItems = new FileStream(strSoldItemsFile, FileMode.Open, FileAccess.Read))
        {
            xdSoldItems.Load(fsSoldItems);
            XmlNodeList xnlSoldItems = xdSoldItems.GetElementsByTagName("SoldItemID");

            foreach (XmlNode xnSoldItem in xnlSoldItems)
                iSoldItemID = int.Parse(xnSoldItem.InnerText);
        }

        iSoldItemID = iSoldItemID + 1;

        using (FileStream fsSoldItems = new FileStream(strSoldItemsFile, FileMode.Create, FileAccess.Write))
        {
            foreach (ListViewItem lviSoldItem in lvwSoldItems.Items)
            {
                XmlElement xeSoldItem = xdSoldItems.CreateElement("SoldItem");
                xeSoldItem.InnerXml = "<SoldItemID>" + iSoldItemID.ToString() + "</SoldItemID>" +
                                      "<ReceiptNumber>" + txtReceiptNumber.Text + "</ReceiptNumber>" +
                                      "<ItemNumber>" + lviSoldItem.SubItems[0].Text + "</ItemNumber>" +
                                      "<ItemName>" + lviSoldItem.SubItems[1].Text + "</ItemName>" +
                                      "<ItemSize>" + lviSoldItem.SubItems[2].Text + "</ItemSize>" +
                                      "<UnitPrice>" + lviSoldItem.SubItems[3].Text + "</UnitPrice>" +
                                      "<DiscountRate>" + lviSoldItem.SubItems[4].Text + "</DiscountRate>" +
                                      "<DiscountAmount>" + lviSoldItem.SubItems[5].Text + "</DiscountAmount>" +
                                      "<SalePrice>" + lviSoldItem.SubItems[6].Text + "</SalePrice>";
                xdSoldItems.DocumentElement.AppendChild(xeSoldItem);
                iSoldItemID++;
            }

            xdSoldItems.Save(fsSoldItems);

            MessageBox.Show("The customer's order has been saved.",
                            "FunDS", MessageBoxButtons.OK,
                            MessageBoxIcon.Information);
        }

        if (File.Exists(strStoreItemsFile))
        {
            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Open, FileAccess.Read))
            {
                xdStoreItems.Load(fsStoreItems);

                XmlNodeList xnlStoreItems = xdStoreItems.GetElementsByTagName("ItemNumber");

                // Remove the items of the list view from the StoreItems table
                foreach (ListViewItem lviStoreItem in lvwSoldItems.Items)
                {
                    foreach (XmlNode xnStoreItem in xnlStoreItems)
                    {
                        if (xnStoreItem.InnerText == lviStoreItem.SubItems[0].Text)
                            xdStoreItems.DocumentElement.RemoveChild(xnStoreItem.ParentNode);
                    }
                }
            }

            using (FileStream fsStoreItems = new FileStream(strStoreItemsFile, FileMode.Create, FileAccess.Write))
            {
                xdStoreItems.Save(fsStoreItems);
            }
        }

        ResetForm();
    }

    private void tmrDateTimeTick(object sender, EventArgs e)
    {
        dtpSaleDate.Value = DateTime.Today;
        lblSaleTime.Text = DateTime.Now.ToLongTimeString();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }
}

On the main menu, click File -> New
When asked whether you want to save, click Save
In the top combo box, make sure the FunDS1 folder is displaying, Set the Save As Type to All Files
Set the File Name to ShoppingSessionReview.cs
Click Save

A Switchboard

A switchboard serves as the central point of an application. It holds a list of the forms used in an application.

Practical Learning: Creating a Switchboard

In the empty document, type the following:

using System;
using System.IO;
using System.Xml;
using System.Drawing;
using System.Windows.Forms;
using System.Collections.Generic;

public class FunDS : Form
{
    private Button btnNewShoppingSession;
    private Button btnStoreItems;
    private Button btnShoppingSessionReview;
    private Button btnNewStoreItem;
    private Button btnEmployees;
    private Button btnEditStoreItem;
    private Button btnNewEmployee;
    private Button btnDeleteStoteItem;
    private Button btnClose;

    public FunDS()
    {
        InitializeComponent();
    }

    private void InitializeComponent()
    {
        // Button: New Shopping Session
        btnNewShoppingSession = new Button();
        btnNewShoppingSession.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnNewShoppingSession.Location = new Point(22, 22);
        btnNewShoppingSession.Size = new System.Drawing.Size(478, 67);
        btnNewShoppingSession.TabIndex = 0;
        btnNewShoppingSession.Text = "New Shopping Session ...";
        btnNewShoppingSession.Click += new System.EventHandler(btnNewShoppingSessionClick);
        Controls.Add(btnNewShoppingSession);

        // Button: Store Items
        btnStoreItems = new Button();
        btnStoreItems.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnStoreItems.Location = new Point(518, 22);
        btnStoreItems.Size = new System.Drawing.Size(478, 67);
        btnStoreItems.TabIndex = 1;
        btnStoreItems.Text = "Store Items ...";
        btnStoreItems.Click += new System.EventHandler(btnStoreItemsClick);
        Controls.Add(btnStoreItems);

        // Button: Shopping Session  Review
        btnShoppingSessionReview = new Button();
        btnShoppingSessionReview.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnShoppingSessionReview.Location = new Point(22, 108);
        btnShoppingSessionReview.Size = new System.Drawing.Size(478, 67);
        btnShoppingSessionReview.TabIndex = 2;
        btnShoppingSessionReview.Text = "Shopping Session Review ...";
        btnShoppingSessionReview.Click += new System.EventHandler(btnShoppingSessionReviewClick);
        Controls.Add(btnShoppingSessionReview);

        // Button: New Store Item
        btnNewStoreItem = new Button();
        btnNewStoreItem.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnNewStoreItem.Location = new Point(518, 108);
        btnNewStoreItem.Size = new System.Drawing.Size(478, 67);
        btnNewStoreItem.TabIndex = 3;
        btnNewStoreItem.Text = "New Store Item ...";
        btnNewStoreItem.Click += new System.EventHandler(btnNewStoreItemClick);
        Controls.Add(btnNewStoreItem);

        // Button: Employees
        btnEmployees = new Button();
        btnEmployees.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnEmployees.Location = new Point(22, 194);
        btnEmployees.Size = new System.Drawing.Size(478, 67);
        btnEmployees.TabIndex = 4;
        btnEmployees.Text = "Employees ...";
        btnEmployees.Click += new System.EventHandler(btnEmployeesClick);
        Controls.Add(btnEmployees);

        // Button: Edit Store Item
        btnEditStoreItem = new Button();
        btnEditStoreItem.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnEditStoreItem.Location = new Point(518, 194);
        btnEditStoreItem.Size = new System.Drawing.Size(478, 67);
        btnEditStoreItem.TabIndex = 5;
        btnEditStoreItem.Text = "Edit Store Item ...";
        btnEditStoreItem.Click += new System.EventHandler(btnEditStoreItemClick);
        Controls.Add(btnEditStoreItem);

        // Button: New Employee
        btnNewEmployee = new Button();
        btnNewEmployee.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnNewEmployee.Location = new Point(22, 283);
        btnNewEmployee.Size = new System.Drawing.Size(478, 67);
        btnNewEmployee.TabIndex = 6;
        btnNewEmployee.Text = "New Employee ...";
        btnNewEmployee.Click += new System.EventHandler(btnNewEmployeeClick);
        Controls.Add(btnNewEmployee);

        // Button: Delete Stote Item
        btnDeleteStoteItem = new Button();
        btnDeleteStoteItem.Font = new System.Drawing.Font("Palatino Linotype", 26.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnDeleteStoteItem.Location = new Point(518, 283);
        btnDeleteStoteItem.Size = new System.Drawing.Size(478, 67);
        btnDeleteStoteItem.TabIndex = 7;
        btnDeleteStoteItem.Text = "Delete Stote Item ...";
        btnDeleteStoteItem.Click += new System.EventHandler(btnDeleteStoteItemClick);
        Controls.Add(btnDeleteStoteItem);

        // Button: Close
        btnClose = new Button();
        btnClose.Font = new System.Drawing.Font("Palatino Linotype", 27.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, 0);
        btnClose.Location = new Point(22, 374);
        btnClose.Size = new System.Drawing.Size(974, 67);
        btnClose.TabIndex = 8;
        btnClose.Text = "Close";
        btnClose.Click += new System.EventHandler(btnCloseClick);
        Controls.Add(btnClose);

        // Form: Fun Department Store
        ClientSize = new System.Drawing.Size(1018, 463);
        StartPosition = FormStartPosition.CenterScreen;
        Text = "FunDS - Fun Department Store";
        Load += new EventHandler(FunDSLoad);
    }

    private void FunDSLoad(object sender, EventArgs e)
    {
        Directory.CreateDirectory(@"C:\Fun Department Store");
    }

    private void btnNewShoppingSessionClick(object sender, EventArgs e)
    {
        NewShoppingSession nss = new NewShoppingSession();
        nss.Show();
    }

    private void btnStoreItemsClick(object sender, EventArgs e)
    {
        StoreItems sis = new StoreItems();
        sis.Show();
    }

    private void btnShoppingSessionReviewClick(object sender, EventArgs e)
    {
        ShoppingSessionReview ssr = new ShoppingSessionReview();
        ssr.Show();
    }

    private void btnNewStoreItemClick(object sender, EventArgs e)
    {
        StoreItemNew sin = new StoreItemNew();
        sin.ShowDialog();
    }

    private void btnEmployeesClick(object sender, EventArgs e)
    {
        Employees clerks = new Employees();
        clerks.Show();
    }

    private void btnEditStoreItemClick(object sender, EventArgs e)
    {
        StoreItemEditor sie = new StoreItemEditor();
        sie.ShowDialog();
    }

    private void btnNewEmployeeClick(object sender, EventArgs e)
    {
        string strEmployeeNumber, strFirstName, strLastName, strCounty,
               strAddress, strCity, strState, strZIPCode, strMaritalStatus;
        int iExemptions;
        double dblHourlySalary;

        EmployeeNew en = new EmployeeNew();
        Random rndEmployeeNumber = new Random();
        XmlDocument xdEmployees = new XmlDocument();
        string strEmployeesFile = @"C:\Fun Department Store\Employees.xml";

        en.txtEmployeeNumber.Text = rndEmployeeNumber.Next(100000, 999999).ToString();

        if (en.ShowDialog() == DialogResult.OK)
        {
            strEmployeeNumber = en.txtEmployeeNumber.Text;
            strFirstName = en.txtFirstName.Text;
            strLastName = en.txtLastName.Text;
            strMaritalStatus = en.cbxMaritalsStatus.Text;
            iExemptions = int.Parse(en.txtExemptions.Text);
            strAddress = en.txtAddress.Text;
            strCity = en.txtCity.Text;
            strCounty = en.txtCounty.Text;
            strState = en.txtState.Text;
            strZIPCode = en.txtZIPCode.Text;
            dblHourlySalary = double.Parse(en.txtHourlySalary.Text);

            if (!File.Exists(strEmployeesFile))
            {
                xdEmployees.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" +
                                    "<Employees></Employees>");
                xdEmployees.Save(strEmployeesFile);
            }

            xdEmployees.Load(strEmployeesFile);

            XmlElement elmXML = xdEmployees.CreateElement("Employee");
            // Create the XML code of the child element of Employee
            string strNewEmployee = "<EmployeeNumber>" + strEmployeeNumber + "</EmployeeNumber>" +
                                    "<FirstName>" + strFirstName + "</FirstName>" +
                                    "<LastName>" + strLastName + "</LastName>" +
                                    "<Address>" + strAddress + "</Address>" +
                                    "<City>" + strCity + "</City>" +
                                    "<County>" + strCounty + "</County>" +
                                    "<State>" + strState + "</State>" +
                                    "<ZIPCode>" + strZIPCode + "</ZIPCode>" +
                                    "<MaritalStatus>" + strMaritalStatus + "</MaritalStatus>" +
                                    "<Exemptions>" + iExemptions + "</Exemptions>" +
                                    "<HourlySalary>" + dblHourlySalary + "</HourlySalary>";
            elmXML.InnerXml = strNewEmployee;
            // Append the new element as a child of employees
            xdEmployees.DocumentElement.AppendChild(elmXML);

            // Save the XML file
            xdEmployees.Save(strEmployeesFile);
        }
    }

    private void btnDeleteStoteItemClick(object sender, EventArgs e)
    {
        StoreItemDelete sid = new StoreItemDelete();
        sid.ShowDialog();
    }

    private void btnCloseClick(object sender, EventArgs e)
    {
        Close();
    }

    [STAThread]
    public static int Main()
    {
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new FunDS());

        return 0;
    }
}

On the main menu, click File -> Exit
When asked whether you want to save, click Save
In the top combo box, make sure the FunDS1 folder is displaying, Set the Save As Type to All Files
Set the File Name to FunDS.cs
Click Save

Building the Application

To build this project, you can use the compiler provides in Microsoft Windows and from the Command Prompt.

Practical Learning: Creating a Switchboard

Display the Command Prompt (Start -> (All) Programs -> Accessories -> Command Prompt)
Type CD\ and press Enter to access the root
Type CD FunDS1 and press Enter to access the folder for the current project

To build the project, type the following code:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\csc /t:winexe FunDS.cs EmployeeNew.cs EmployeeEditor.cs Employees.cs Manufacturer.cs Category.cs SubCategory.cs StoreItemNew.cs StoreItemEditor.cs StoreItemDelete.cs Inventory.cs PointOfSale.cs ShoppingSessionReview.cs

Press Enter

Application Testing

If you want to test the application, use the following values.

Item #	Manufacturer	Category	Sub-Category	Item Name	Item Size	Unit Price	Discount Rate
177314	Ralph Lauren	Girls	Shirts	Girls 2-6X Short-Sleeved Mesh Polo Shirt	3T	34.95
729530	Kenneth Cole	Women	Dresses	Three-Quarter Sleeved Dress	M	164.5	50
307368	Polo Ralph Lauren	Men	Pants	Classic Straight-Leg Jeans	30W - 29L	84.85	15
220573	Nautica	Baby Girls		Baby Girls 12-24 Months Lace Two-Piece Set	12M	40
806888	Guess	Girls	Dresses	Girls 2-6X Denim Print Ruffled Dress	2T	34.95
683079	Anne Klein	Women	Skirts	Pencil Skirt	2	54
848428	Ralph Lauren	Boys	Sweaters	Boys 2-7 Long-Sleeved Cable Crewneck T-Shirt	4	55
683626	Ralph Lauren	Women	Dresses	Structured Scoopneck Ponte Dress	0	195	60

Employee #	First Name	Last Name	Address	City	Country	State	ZIP Code	Marital Status	Exemptions	Hourly Salary
952748	David	Evans	5102 Piedmont Rd	Silver Spring	Montgomery	MD	20910	Single	0	17.25
606384	Robert	Gibson	10324 Marina Ave	College Park	Prince George	MD	20742	Single	1	22.25

Employee #	Item #	Tendered
606384	177314	50

Employee #	First Name	Last Name	Address	City	Country	State	ZIP Code	Marital Status	Exemptions	Hourly Salary
428041	Jeannine	Hewsen	2418 Woodwell Rd	Rockville	Montgomery	MD	20850	Married	2	34.05
172847	Carl	Lowry	7447 Emiry Str	Alexandria	(Independent)	VA	22314	Single	2	26.85
927048	Henry	Meuer	802 Wheeler St	York	York	PA	17401	Married	0	8.95
837405	Herbert	Mann	6218 Willimon Ave	Wilmington	New Castle	DE	19801	Married	2	14.75

Item #	Manufacturer	Category	Sub-Category	Item Name	Item Size	Unit Price	Discount Rate
580040	Cole Haan	Women	Handbags	Victoria Zip-Top Tote Bag		298
795081	Lauren by Ralph Lauren	Men	Pants	Mid-Weight Flat-Front Wool Trouser Pants	36W 32L	65	25
948596	Tommy Hilfiger	Men	Shirts	Texture Oxford Slim Fit Long Sleeve Dress Shirt	17 - 34/35	47.75
360825	Lauren by Ralph Lauren	Women	Accessories	Printed Silk Scarf		45
383511	Calvin Klein	Men	Pants	Straight Leg Jean in Black Wash	32/30	45
294148	Lauren by Ralph Lauren	Men	Pants	Mid-Weight Flat-Front Wool Trouser Pants	36W 29L	65
559717	Guess	Girls	Dresses	Girls 2-6X Denim Print Ruffled Dress	3T	34.95
830486	AK Anne Klein	Women	Skirts	Seamless Textured Pencil Skirt	S	65.95