Example Application: Bethesda Car Rental

	Example Application: Bethesda Car Rental

Description

This is a file-based application that uses the dictionary-types of the .NET Framework's built-in collection classes.

The application is used by a car rental company. To start, a list of cars and the employees of the company are created. When a customer comes to rent a car, an account is created. This would be used for a rental order. To make this application simple, only the most basic pieces of information are collected. These include the customer's full name and the driver's license number.

During rental order processing, a clerk selects the customer and the type of car he or she wants to rent.

Practical Learning: Introducing Dictionary Collections

Start Microsoft Visual C#
Create a new Windows Application named BethesdaCarRental1
To add a new form to the project, in the Solution Explorer, right-click BethesdaCarRental1 -> Add -> Windows Form...
Set the Name to RentalRates and press Enter

Add a ListView to the form and create its Columns as follows:

(Name)	Text	TextAlign	Width
colCategory	Category		90
colDaily	Daily	Right
colWeekly	Weekly	Right
colMonthly	Monthly	Right
colWeekend	Weekend	Right

Create its Items as follows:

ListViewItem	SubItems	SubItems	SubItems	SubItems
	Text	Text	Text	Text
Economy	35.95	32.75	28.95	24.95
Compact	39.95	35.75	32.95	28.95
Standard	45.95	39.75	35.95	32.95
Full Size	49.95	42.75	38.95	35.95
Mini Van	55.95	50.75	45.95	42.95
SUV	55.95	50.75	45.95	42.95
Truck	42.75	38.75	35.95	32.95
Van	69.95	62.75	55.95	52.95

Complete the design of the form as follows:
To add a new form to the application, in the Solution Explorer, right-click BethesdaCarRental1 -> Add -> Windows Form...
Set the Name to Employees and click Add
From the Toolbox, add a ListView to the form

While the new list view is still selected, in the Properties window, click the ellipsis button of the Columns field and create the columns as follows:

(Name)	Text	TextAlign	Width
colEmployeeNumber	Empl #		45
colFirstName	First Name		65
colLastName	Last Name		65
colFullName	Full Name		140
colTitle	Title		120
colHourlySalary	Hourly Salary	Right	75

Design the form as follows:

Control	Text	Name	Other Properties
ListView		lvwEmployees	Anchor: Top, Bottom, Left, Right FullRowSelect: True GridLines: True View: Details
Button	New Employee...	btnNewEmployee
Button	Close	btnClose

To add another form to the application, in the Solution Explorer, right- click BethesdaCarRental1 -> Add -> Windows Form...
Set the Name to EmployeeEditor and click Add

Design the form as follows:

Control	Text	Name	Properties
Label	&Employee #:
MaskedTextBox		txtEmployeeNumber	Mask: 00-000 Modifiers: public
Label	First Name:
TextBox		txtFirstName	Modifiers: public
Label	Last Name:
TextBox		txtLastName	Modifiers: public
Label	Full Name:
TextBox		txtFullName	Enabled: False Modifiers: public
Label	Title:
TextBox		txtTitle	Modifiers: public
Label	Hourly Salary:
TextBox		txtHourlySalary	Modifiers: public TextAlign: Right
Button	OK	btnOK	DialogResult: OK
Button	Cancel	btnCancel	DialogResult: Cancel
Form			AcceptButton: btnOK CancelButton: btnCancel FormBorderStyle: FixedDialog MaximizeBox: False MinimizeBox: False ShowInTaskbar: False

Click the Last Name text box
In the Properties window, click the Events button and double-click Leave

Implement the event as follows:

// This code is used to create and display the customer's full name
private void txtLastName_Leave(object sender, EventArgs e)
{
    string strFirstName = txtFirstName.Text;
    string strLastName = txtLastName.Text;
    string strFullName;

    if (strFirstName.Length == 0)
        strFullName = strLastName;
    else
        strFullName = strLastName + ", " + strFirstName;

    txtFullName.Text = strFullName;
}

To add a new class to the project, in the Class View, right- click BethesdaCarRental1 -> Add -> Class...
Set the Class Name to Employee and click Add

Change the Employee.cs file as follows:

using System;

namespace BethesdaCarRental1
{
    [Serializable]
    public class Employee
    {
        public string FirstName;
        public string LastName;
        public string Title;
        public double HourlySalary;

        public string FullName
        {
            get { return LastName + ", " + FirstName; }
        }

        // This default constructor says that
	// the employee is not defined
        public Employee()
        {
            FirstName = "Unknown";
            LastName = "Unknown";
            Title = "N/A";
            HourlySalary = 0.00;
        }

        // This constructor completely defines an employee
        public Employee(string fname, string lname,
                        string title, double salary)
        {
            FirstName = fname;
            LastName = lname;
            Title = title;
            HourlySalary = salary;
        }
    }
}

To add a new form to the application, on the main menu, click Project -> Add Windows Forms
Set the Name to Customers and press Enter
From the Toolbox, add a ListView to the form

While the new list view is still selected, in the Properties window, click the ellipsis button of the Columns field and create the columns as follows:

(Name)	Text	Width
colDrvLicNbr	Driver's Lic. #	100
colFullName	Full Name	100
colAddress	Address	160
colCity	City	100
colState	State	38
colZIPCode	ZIPCode

Design the form as follows:

Control	Text	Name	Other Properties
ListView		lvwCustomers	View: Details GridLines: True FullRowSelect: True
Button	New Customer...	btnNewCustomer
Button	Close	btnClose

To add another form to the application, on the main menu, click Project -> Add Windows Forms
Set the Name to CustomerEditor and click Add

Design the form as follows:

Control	Text	Name	Properties
Label	Driver's Lic. #:
TextBox		txtDrvLicNbr	Modifiers: Public
Label	State:
ComboBox		cbxStates	Modifiers: Public Items: AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY
Label	Full Name:
TextBox		txtFullName	Modifiers: Public
Label	Address:
TextBox		txtAddress	Modifiers: Public
Label	City:
TextBox		txtCity	Modifiers: Public
Label	ZIP Code:
TextBox		txtZIPCode	Modifiers: Public
Button	OK	btnOK	DialogResult: OK
Button	Close	btnCancel	DialogResult: Cancel
Form			AcceptButton: btnOK CancelButton: btnCancel FormBorderStyle: FixedDialog MaximizeBox: False MinimizeBox: False ShowInTaskbar: False

To add a new class to the project, in the Class View, right-click BethesdaCarRental1 -> Add -> Class...
Set the Class Name to Customer and click Finish

Change the Customer.cs file as follows:

using System;

namespace BethesdaCarRental1
{
    [Serializable]
    public class Customer
    {
        public string FullName;
        public string Address;
        public string City;
        public string State;
        public string ZIPCode;

        public Customer()
        {
            FullName = "";
            Address = "";
            City = "";
            State = "";
            ZIPCode = "";
        }

        // This constructor defines a customer
        public Customer(string fName,
                        string adr, string ct,
                        string ste, string zip)
        {
            FullName = fName;
            Address = adr;
            City = ct;
            State = ste;
            ZIPCode = zip;
        }
    }
}

Save all

Copy the following pictures to any folder somewhere on your computer (this is simply an example of preparing the pictures of cars you would include in your database application):


BMW: 335i	Chevrolet Avalanche

Honda Accord	Mazda Miata

Chevrolet Aveo	Ford E150XL

Buick Lacrosse	Honda Civic

Ford F-150	Mazda Mazda5

Volvo S40	Land Rover LR3

Return to your programming environment
To add a new form to the application, in the Solution Explorer, right-click BethesdaCarRental1 -> Add -> Windows Forms
Set the Name to CarEditor and click Add

Design the form as follows:

Control	Text	Name	Other Properties
Label	Text #
TextBox		txtTagNumber
Label	Make:
TextBox		txtMake
Label	Model:
TextBox		txtModel
Label	Year:
TextBox		txtYear
Label	Category:
ComboBox		cboCategories	DropDownStyle: DropDownList
ComboBox		cboCategories	Items:	Economy Compact Standard Full Size Mini Van SUV Truck Van
PictureBox		pbxCar	SizeMode: Zoom
CheckBox	CD Player	chkCDPlayer	CheckAlign: MiddleRight
CheckBox	DVD Player	chkDVDPlayer	CheckAlign: MiddleRight
Button	Select Car Picture...	btnSelectPicture
CheckBox	Available	chkAvailable	CheckAlign: MiddleRight
Label	Picture Name	lblPictureName
Button	Submit	btnSubmit
Button	Close	btnClose	DialogResult: Cancel
OpenFileDialog	(Name): dlgOpen Title: Select Item Picture DefaultExt: jpg Filter: JPEG Files (.jpg,.jpeg)\|.jpg\|GIF Files (.gif)\|.gif\|Bitmap Files (.bmp)\|.bmp\|PNG Files (.png)\|*.png
Form			FormBorderStyle: FixedDialog MaximizeBox: False MinimizeBox: False ShowInTaskbar: False

Double-click the Select Car Picture button and implement its event as follows:

private void btnSelectPicture_Click(object sender, EventArgs e)
{
    if (dlgPicture.ShowDialog() == DialogResult.OK)
    {
        lblPictureName.Text = dlgPicture.FileName;
        pbxCar.Image = Image.FromFile(lblPictureName.Text);
    }
}

To add a new class to the project, in the Class View, right-click BethedaCarRental1 -> Add -> Class...
Set the Class Name to Car and click Add

Change the file as follows:

using System;

namespace BethesdaCarRental1
{
    [Serializable]
    public class Car
    {
        public string Make;
        public string Model;
        public int Year;
        public string Category;
        public bool HasCDPlayer;
        public bool HasDVDPlayer;
        public bool IsAvailable;

        public Car()
        {
            Make = "";
            Model = "";
            Year = 0;
            Category = "";
            HasCDPlayer = false;
            HasDVDPlayer = false;
            IsAvailable = false;
        }

        public Car(string mk, string mdl,
                   int yr, string cat, bool cd,
                   bool  dvd, bool avl)
        {
            Make = mk;
            Model = mdl;
            Year = yr;
            Category = cat;
            HasCDPlayer = cd;
            HasDVDPlayer = dvd;
            IsAvailable = avl;
        }
    }
}

To add a new class to the project, in the Class View, right-click BethesdaCarRental -> Add -> Class...
Set the Class Name to RentalOrder and press Enter

Access the RentalOrder.h file and change it as follows:

using System;

namespace BethesdaCarRental1
{
    [Serializable]
    public class RentalOrder
    {
        public string EmployeeNumber;
        // The following flag will allow us to update/know whether
        // * The car is currently being used by the customer.
        //   That is, if the car has been picked up by the customer
        // * The customer has brought the car back
        public string OrderStatus;
        // Because every car has a tag number
        // and that tag number will not change
        // during the lifetime of a car (while the car remains with our
	// car rental company, we will 
        // use only the tag number here.
        // The other pieces of information will 
        // be retrieved from the list of cars
        public string CarTagNumber;
        // We will identify the customer by the number
        // and the name on his or her driver's license
        public string CustomerDrvLicNbr;
        public string CustomerName;
        // Although he or she may keep the same driver's 
        // license number for a lifetime, a customer who 
        // rents cars at different times with this company 
	// over months or years may have different addresses.
        // Therefore, although we will primarily retrieve the 
        // customer's address from the list of customers,
        // we will give the clerk the ability to change this 
        // information on a rental order. This means that the 
        // same customer could have different information on 
        // different rental orders.
	// For this reason, each rental order will its own set
	// of these pieces of information
        public string CustomerAddress;
        public string CustomerCity;
        public string CustomerState;
        public string CustomerZIPCode;
        public string CarCondition;
        public string TankLevel;
        // This information will be entered when the car is being rented
        public int MileageStart;
        // This information will be entered when the car is brought back
        public int MileageEnd;
        // This information will be entered when the car is being rented
        public DateTime DateStart;
        // This information will be entered when the car is brought back
        public DateTime DateEnd;
        public int Days;
        // This information will be entered when the car is being rented
        public double RateApplied;
        // This calculation should occur when the car is brought back
        public double SubTotal;
        public double TaxRate;
        public double TaxAmount;
        public double OrderTotal;

        public RentalOrder()
        {
        }
    }
}

To add a new form to the project, in the Solution Explorer, right-click BethesdaCarRenatl -> Add -> Windows Form...
Set the Name to OrderProcessing and press Enter

Design the form as follows:

Control	Text	Name	Other Properties
Label	Processed By:		AutoSize: False BackColor: Gray BorderStyle: FixedSingle ForeColor: White TextAlign: MiddleLeft
Label	Employee #:
MaskedTextBox		txtEmployeeNumber	Mask: 00-000
Label	Employee Name:
TextBox		txtEmployeeName
Label	Processed For		AutoSize: False BackColor: Gray BorderStyle: FixedSingle ForeColor: White TextAlign: MiddleLeft
Label	Driver's Lic #:
TextBox		txtDrvLicNumber
Label	Cust Name:
TextBox		txtCustomerName
Label	Address:
TextBox		txtCustomerAddress
Label	City:
TextBox		txtCustomerCity
Label	State:
ComboBox		cbxCustomerStates	DropDownStyle: DropDownList Sorted: True Items: AL, AK, AZ, AR, CA, CO, CT, DE, DC, FL, GA, HI, ID, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MS, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY
Label	ZIP Code
TextBox		txtCustomerZIPCode
Label	Car Selected		AutoSize: False BackColor: Gray BorderStyle: FixedSingle ForeColor: White TextAlign: MiddleLeft
Label	Tag Number:
TextBox		txtTagNumber
Label	Car Condition:
ComboBox		cbxCarConditions	Sorted: True Items: Needs Repair Drivable Excellent
Label	Make:
TextBox		txtMake
Label	Model:
TextBox		txtModel
Label	Year:
TextBox		txtCarYear
label	Tank Level:
ComboBox		cbxTankLevels	Empty 1/4 Empty 1/2 Full 3/4 Full Full
Label	Mileage Start:
TextBox		txtMileageStart	TextAlign: Right
Label	Mileage End:
TextBox		txtMileageEnd	TextAlign: Right
Label	Order Timing		AutoSize: False BackColor: Gray BorderStyle: FixedSingle ForeColor: White TextAlign: MiddleLeft
Label	Start Date:
DateTimePicker		dtpStartDate
Label	End Date:
DateTimePicker		dtpEndDate
Label	Days:
TextBox	0	txtDays	TextAlign: Right
Label	Order Status
ComboBox		cbxOrderStatus	Items: Car On Road Car Returned Order Reserved
Label	Order Evaluation		AutoSize: False BackColor: Gray BorderStyle: FixedSingle ForeColor: White TextAlign: MiddleLeft
Label	Rate Applied:
TextBox	0.00	txtRateApplied	TextAlign: Right
Button	Rental Rates	btnRentalRates
Label	Sub-Total:
TextBox	0.00	txtSubTotal	TextAlign: Right
Button	Calculate	btnCalculate
Label	Tax Rate:
TextBox	7.75	txtTaxRate	TextAlign: Right
Label	%
Button	Save	btnSave
Label	Tax Amount:
TextBox	0.00	txtTaxAmount	TextAlign: Right
Button	Print...	btnPrint
Label	Order Total:
TextBox	0.00	txtOrderTotal	TextAlign: Right
Button	Print Preview...	btnPrintPreview
Label	Receipt #:
TextBox	0	txtReceiptNumber
Button	Open	btnOpen
Button	New Rental Order/Reset	btnNewRentalOrder
Button	Close	btnClose

On to the Order Processing form, double-click the Start Date date time picker control

Implement the event as follows:

private void dtpStartDate_ValueChanged(object sender, EventArgs e)
{
    dtpEndDate.Value = dtpStartDate.Value;
}

Return to the Order Processing form and double-click the End Date control

Implement its Click event as follows:

// This event approximately evaluates the number of days as a
// difference between the end date and the starting date
private void dtpEndDate_ValueChanged(object sender, EventArgs e)
{
    int days;

    DateTime dteStart = this.dtpStartDate.Value;
    DateTime dteEnd = this.dtpEndDate.Value;

    // Let's calculate the difference in days
    TimeSpan tme = dteEnd - dteStart;
    days = tme.Days;

    // If the customer returns the car the same day, 
    // we consider that the car was rented for 1 day
    if (days == 0)
        days = 1;

    txtDays.Text = days.ToString();
    // At any case, we will let the clerk specify the actual number of days
}

Return to the Order Processing form and double-click the Rental Rates button

Implement its event as follows:

private void btnRentalRates_Click(object sender, EventArgs e)
{
    RentalRates wndRates = new RentalRates();
    wndRates.Show();
}

Return to the Order Processing form and double-click the Calculate button

Implement its event as follows:

private void btnCalculate_Click(object sender, EventArgs e)
{
    int    Days = 0;
    double RateApplied = 0.00;
    double SubTotal = 0.00;
    double TaxRate = 0.00;
    double TaxAmount = 0.00;
    double OrderTotal = 0.00;

    try
    {
        Days = int.Parse(this.txtDays.Text);
    }
    catch (FormatException)
    {
        MessageBox.Show("Invalid Number of Days");
    }

    try
    {
        RateApplied = double.Parse(txtRateApplied.Text);
    }
    catch (FormatException)
    {
        MessageBox.Show("Invalid Amount for Rate Applied");
    }

    SubTotal = Days * RateApplied;
    txtSubTotal.Text = SubTotal.ToString("F");

    try
    {
        TaxRate = double.Parse(txtTaxRate.Text);
    }
    catch (FormatException)
    {
        MessageBox.Show("Invalid Tax Rate");
    }

    TaxAmount = SubTotal * TaxRate / 100;
    txtTaxAmount.Text = TaxAmount.ToString("F");

    OrderTotal = SubTotal + TaxAmount;
    txtOrderTotal.Text = OrderTotal.ToString("F");
}

Return to the Order Processing form
From the Printing section of the Toolbox, click PrintDocument and click the form
In the Properties window, set its (Name) to docPrint and press Enter

Under the form, double-click docPrint and implement its event as follows:

private void docPrint_PrintPage(object sender,
	System.Drawing.Printing.PrintPageEventArgs e)
{
    e.Graphics.DrawLine(new Pen(Color.Black, 2), 80, 90, 750, 90);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 80, 93, 750, 93);

    string strDisplay = "Bethesda Car Rental";
    System.Drawing.Font fntString = new Font("Times New Roman", 28,
                        FontStyle.Bold);
    e.Graphics.DrawString(strDisplay, fntString,
                        Brushes.Black, 240, 100);

    strDisplay = "Car Rental Order";
    fntString = new System.Drawing.Font("Times New Roman", 22,
                        FontStyle.Regular);
    e.Graphics.DrawString(strDisplay, fntString,
                        Brushes.Black, 320, 150);

    e.Graphics.DrawLine(new Pen(Color.Black, 1), 80, 187, 750, 187);
    e.Graphics.DrawLine(new Pen(Color.Black, 2), 80, 190, 750, 190);

    fntString = new System.Drawing.Font("Times New Roman", 12,
                FontStyle.Bold);
    e.Graphics.DrawString("Receipt #:  ", fntString,
                Brushes.Black, 100, 220);
    fntString = new System.Drawing.Font("Times New Roman", 12,
                FontStyle.Regular);
    e.Graphics.DrawString(txtReceiptNumber.Text, fntString,
                                  Brushes.Black, 260, 220);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 240, 380, 240);

    fntString = new System.Drawing.Font("Times New Roman", 12,
                FontStyle.Bold);
    e.Graphics.DrawString("Processed By:  ", fntString,
                Brushes.Black, 420, 220);
    fntString = new System.Drawing.Font("Times New Roman", 12,
                FontStyle.Regular);
    e.Graphics.DrawString(txtEmployeeName.Text, fntString,
                                  Brushes.Black, 550, 220);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 420, 240, 720, 240);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);

    e.Graphics.FillRectangle(Brushes.Gray,
			 new Rectangle(100, 260, 620, 20));
    e.Graphics.DrawRectangle(Pens.Black,
			 new Rectangle(100, 260, 620, 20));

    e.Graphics.DrawString("Customer", fntString,
                                  Brushes.White, 100, 260);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Driver's License #: ", fntString,
                                  Brushes.Black, 100, 300);
    e.Graphics.DrawString("Name: ", fntString,
                                 Brushes.Black, 420, 300);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtDrvLicNumber.Text, fntString,
                                  Brushes.Black, 260, 300);
    e.Graphics.DrawString(txtCustomerName.Text, fntString,
                                  Brushes.Black, 540, 300);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 320, 720, 320);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Address: ", fntString,
                                  Brushes.Black, 100, 330);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtCustomerAddress.Text, fntString,
                                  Brushes.Black, 260, 330);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 350, 720, 350);

    strDisplay = txtCustomerCity.Text + " " +
                         cbxCustomerStates.Text + " " +
                         txtCustomerZIPCode.Text;
    fntString = new System.Drawing.Font("Times New Roman",
 		12, FontStyle.Regular);
    e.Graphics.DrawString(strDisplay, fntString,
                                  Brushes.Black, 260, 360);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 260, 380, 720, 380);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);

    e.Graphics.FillRectangle(Brushes.Gray,
		new Rectangle(100, 410, 620, 20));
    e.Graphics.DrawRectangle(Pens.Black,
		new Rectangle(100, 410, 620, 20));

    e.Graphics.DrawString("Car Information", fntString,
                                  Brushes.White, 100, 410);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Tag #: ", fntString,
                                  Brushes.Black, 100, 450);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtTagNumber.Text, fntString,
                                  Brushes.Black, 260, 450);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 470, 380, 470);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Year: ", fntString,
                                  Brushes.Black, 420, 450);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtCarYear.Text, fntString,
                                  Brushes.Black, 530, 450);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 420, 470, 720, 470);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Make: ", fntString,
                                  Brushes.Black, 100, 480);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtMake.Text, fntString,
                                  Brushes.Black, 260, 480);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 500, 380, 500);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Model: ", fntString,
                                  Brushes.Black, 420, 480);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtModel.Text, fntString,
                                  Brushes.Black, 530, 480);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 420, 500, 720, 500);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Car Condition: ", fntString,
                                  Brushes.Black, 100, 510);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(cbxCarConditions.Text, fntString,
                                  Brushes.Black, 260, 510);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 100, 530, 380, 530);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Tank Level: ", fntString,
                                  Brushes.Black, 420, 510);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(cbxTankLevels.Text, fntString,
                                  Brushes.Black, 530, 510);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 420, 530, 720, 530);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Mileage Start:", fntString,
                                  Brushes.Black, 100, 540);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtMileageStart.Text, fntString,
                                  Brushes.Black, 260, 540);
    e.Graphics.DrawLine(new Pen(Color.Black, 1), 
				100, 560, 380, 560);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Mileage End:", fntString,
                          Brushes.Black, 420, 540);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtMileageEnd.Text, fntString,
                          Brushes.Black, 530, 540);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			420, 560, 720, 560);

    e.Graphics.FillRectangle(Brushes.Gray,
			 new Rectangle(100, 590, 620, 20));
    e.Graphics.DrawRectangle(Pens.Black,
			 new Rectangle(100, 590, 620, 20));

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Order Timing Information", fntString,
                          Brushes.White, 100, 590);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Start Date:", fntString,
                           Brushes.Black, 100, 620);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(dtpStartDate.Value.ToString("D"),
			  fntString, Brushes.Black, 260, 620);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			100, 640, 720, 640);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("End Date:", fntString,
                          Brushes.Black, 100, 650);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(dtpEndDate.Value.ToString("D"), fntString,
                          Brushes.Black, 260, 650);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			100, 670, 520, 670);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Days:", fntString,
                          Brushes.Black, 550, 650);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtDays.Text, fntString,
                                  Brushes.Black, 640, 650);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			550, 670, 720, 670);

    e.Graphics.FillRectangle(Brushes.Gray,
			new Rectangle(100, 700, 620, 20));
    e.Graphics.DrawRectangle(Pens.Black,
			 new Rectangle(100, 700, 620, 20));

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Order Evaluation", fntString,
                          Brushes.White, 100, 700);

    StringFormat fmtString = new StringFormat();
    fmtString.Alignment = StringAlignment.Far;

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Rate Applied:", fntString,
                          Brushes.Black, 100, 740);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtRateApplied.Text, fntString,
                          Brushes.Black, 300, 740, fmtString);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			100, 760, 380, 760);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Tax Rate:", fntString,
                          Brushes.Black, 420, 740);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtTaxRate.Text, fntString,
                          Brushes.Black, 640, 740, fmtString);
    e.Graphics.DrawString("%", fntString,
                          Brushes.Black, 640, 740);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			420, 760, 720, 760);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Sub-Total:", fntString,
                          Brushes.Black, 100, 770);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtSubTotal.Text, fntString,
                          Brushes.Black, 300, 770, fmtString);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			100, 790, 380, 790);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Tax Amount:", fntString,
                                  Brushes.Black, 420, 770);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtTaxAmount.Text, fntString,
                          Brushes.Black, 640, 770, fmtString);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			420, 790, 720, 790);

    fntString = new Font("Times New Roman", 12, FontStyle.Bold);
    e.Graphics.DrawString("Order Total:", fntString,
                                  Brushes.Black, 420, 800);
    fntString = new Font("Times New Roman", 12, FontStyle.Regular);
    e.Graphics.DrawString(txtOrderTotal.Text, fntString,
                          Brushes.Black, 640, 800, fmtString);
    e.Graphics.DrawLine(new Pen(Color.Black, 1),
			420, 820, 720, 820);
}

Return to the Order Processing form
From the Printing section of the Toolbox, click PrintDialog and click the form
In the Properties window, change its Name to dlgPrint
Still in the Properties windows, set its Document property to docPrint

On the Order Processing form, double-click the Print button and implement its event as follows:

private void btnPrint_Click(object sender, EventArgs e)
{
    if (dlgPrint.ShowDialog() == DialogResult.OK)
        docPrint.Print();
}

Return to the Order Processing form
From the Printing section of the Toolbox, click PrintPreviewDialog and click the form
In the Properties window, change its (Name) to dlgPrintPreview
Still in the Properties windows, set its Document property to docPrint
On the Order Processing form, double-click the Print Preview button

Implement the event as follows:

private void btnPrintPreview_Click(object sender, EventArgs e)
{
    dlgPrintPreview.ShowDialog();
}

In the Solution Explorer, right-click Form1.cs and click Rename
Type Central.cs and press Enter twice

Design the form as follows:

Control	Text	Name
Button	Customers &Rental Orders	btnRentalOrders
Button	C&ars	btnCars
Button	&Employees	btnEmployees
Button	&Customers	btnCustomers
Button	C&lose	btnClose

Double-click the Rental Orders button and implement its event as follows:

private void btnRentalOrders_Click(object sender, EventArgs e)
{
    OrderProcessing dlgOrder = new OrderProcessing();
    dlgOrder.ShowDialog();
}

Return to the Central form

Double-click the Cars button and implement its event as follows:

private void btnCars_Click(object sender, EventArgs e)
{
    CarEditor dlgCars = new CarEditor();
    dlgCars.ShowDialog();
}

Return to the Central form

Double-click the Employees button and implement its event as follows:

private void btnEmployees_Click(object sender, EventArgs e)
{
    Employees dlgEmployees = new Employees();
    dlgEmployees.ShowDialog();
}

Return to the Central form

Double-click the Customers button and implement its event as follows:

private void btnCustomers_Click(object sender, EventArgs e)
{
    Customers dlgCustomers = new Customers();
    dlgCustomers.ShowDialog();
}

Return to the Central form

Double-click the Close button and implement its event as follows:

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

Save all

Creating a Dictionary-Based Collection Class

To support dictionary-based lists, the .NET Framework provides support for dictionary-based collection through two classes: Hashtable and SortedList. Both classes implement:

the IDictionary: This makes it possible to use the DictionaryEntry class to access a key/value item
the ICollection: This makes it possible to know the number of items in the list
the IEnumerable: This makes it possible to use the foreach loop to enumerate the members of the list
and the ICloneable interfaces.

Practical Learning: Creating a Dictionary Variable

Access the CarEditor form and double-click an unoccupied area of its body

Implement the Load event as follows:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

namespace BethesdaCarRental1a
{
    public partial class CarEditor : Form
    {
        Dictionary<string, Car> lstCars;

        public CarEditor()
        {
            InitializeComponent();
        }

        private void btnSelectPicture_Click(object sender, EventArgs e)
        {
            if (dlgPicture.ShowDialog() == DialogResult.OK)
            {
                lblPictureName.Text = dlgPicture.FileName;
                pbxCar.Image = Image.FromFile(lblPictureName.Text);
            }
        }

        private void CarEditor_Load(object sender, EventArgs e)
        {
            Car vehicle = new Car();
            BinaryFormatter bfmCars = new BinaryFormatter();

            // This is the file that holds the list of items
            string FileName = @"C:\Bethesda Car Rental\Cars.crs";
            lblPictureName.Text = ".";

            if (File.Exists(FileName))
            {
                FileStream stmCars = new FileStream(FileName,
                                                    FileMode.Open,
                                                    FileAccess.Read,
                                                    FileShare.Read);
                try
                {
                    // Retrieve the list of cars
                    lstCars  =
		 (Dictionary<string, Car>)bfmCars.Deserialize(stmCars);
                }
                finally
                {
                    stmCars.Close();
                }
            }
            else
                lstCars = new Dictionary<string, Car>();
        }
    }
}

Display the Order Processing form
Right-click the Order Processing form and click View Code

Make the following changes:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

namespace BethesdaCarRental1a
{
    public partial class RentalOrders : Form
    {
        int ReceiptNumber;
        SortedList<int, RentalOrder> lstRentalOrders;

        public RentalOrders()
        {
            InitializeComponent();
        }

	. . . No Change
    }
}

Save all

Adding Items to the Collection

To add an item to the list, you can call the Add() method. The syntax of the System.Collections.Hashtable.Add() and the System.Collections.SortedList.Add() methods is:

public virtual void Add(object Key, object Value);

The syntax of the System.Collections.Generic.Dictionary.Add(), the System.Collections.Generic.SortedDictionary.Add(), and the System.Collections.Generic.SortedList.Add() method is:

public void Add(TKey key, TValue value);

As you can see, you must provide the key and the value as the first and second arguments to the method respectively.

Practical Learning: Adding Items to the Collection

Display the CarEditor form

On the CarEditor form, double-click the Submit button and implement its Click event as follows:

private void btnSubmit_Click(object sender, EventArgs e)
{
    Car vehicle = new Car();
    FileStream stmCars = null;
    BinaryFormatter bfmCars = new BinaryFormatter();
    Directory.CreateDirectory(@"C:\Bethesda Car Rental");
    string strFilename = @"C:\Bethesda Car Rental\Cars.crs";

    if (txtTagNumber.Text.Length == 0)
    {
        MessageBox.Show("You must enter the car's tag number");
        return;
    }

    if (txtMake.Text.Length == 0)
    {
        MessageBox.Show("You must specify the car's manufacturer");
        return;
    }

    if (txtModel.Text.Length == 0)
    {
        MessageBox.Show("You must enter the model of the car");
        return;
    }

    if (txtYear.Text.Length == 0)
    {
        MessageBox.Show("You must enter the year of the car");
        return;
    }

    // Create a car
    vehicle.Make = txtMake.Text;
    vehicle.Model = txtModel.Text;
    vehicle.Year = int.Parse(txtYear.Text);
    vehicle.Category = cbxCategories.Text;
    vehicle.HasCDPlayer = chkCDPlayer.Checked;
    vehicle.HasDVDPlayer = chkDVDPlayer.Checked;
    vehicle.IsAvailable = chkAvailable.Checked;

    // Call the Add method of our collection class to add the car
    lstCars.Add(txtTagNumber.Text, vehicle);

    // Save the list
    stmCars = new FileStream(strFilename,
                             FileMode.Create,
                             FileAccess.Write,
                             FileShare.Write);

    try
    {
        bfmCars.Serialize(stmCars, lstCars);

        if (lblPictureName.Text.Length != 0)
        {
            FileInfo flePicture = new FileInfo(lblPictureName.Text);
            flePicture.CopyTo(@"C:\Bethesda Car Rental\" +
                              txtTagNumber.Text +
                              flePicture.Extension);
        }

        txtTagNumber.Text = "";
        txtMake.Text = "";
        txtModel.Text = "";
        txtYear.Text = "";
        cbxCategories.Text = "Economy";
        chkCDPlayer.Checked = false;
        chkDVDPlayer.Checked = false;
        chkAvailable.Checked = false;
        lblPictureName.Text = ".";
        pbxCar.Image = null;
    }
    finally
    {
        stmCars.Close();
    }
}

Display the Customers form and double-click an unoccupied area of its body

Change the file as follows:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

namespace BethesdaCarRental1a
{
    public partial class Customers : Form
    {
        Dictionary<string, Customer> lstCustomers;

        public Customers()
        {
            InitializeComponent();
        }

        internal void ShowCustomers()
        {
        }

        private void Customers_Load(object sender, EventArgs e)
        {
            lstCustomers = new Dictionary<string, Customer>();
            BinaryFormatter bfmCustomers = new BinaryFormatter();

            // This is the file that holds the list of parts
            string strFilename = @"C:\Bethesda Car Rental\Customers.crc";

            if (File.Exists(strFilename))
            {
                FileStream stmCustomers = new FileStream(strFilename,
                                                         FileMode.Open,
                                                         FileAccess.Read,
                                                         FileShare.Read);

                try
                {
                    // Retrieve the list of employees from file
                    lstCustomers =
            (Dictionary<string,
                     Customer>)
                bfmCustomers.Deserialize(stmCustomers);
                }
                finally
                {
                    stmCustomers.Close();
                }
            }

            ShowCustomers();
        }
    }
}

Return to the Customers form and double-click the New Customer button

Implement its event as follows:

private void btnNewCustomer_Click(object sender, EventArgs e)
{
    CustomerEditor editor = new CustomerEditor();
    Directory.CreateDirectory(@"C:\Bethesda Car Rental");

    if (editor.ShowDialog() == DialogResult.OK)
    {
        if (editor.txtDrvLicNbr.Text == "")
        {
            MessageBox.Show("You must provide the driver's " +
                            "license number of the customer");
            return;
        }

        if (editor.txtFullName.Text == "")
        {
            MessageBox.Show("You must provide the employee's full name");
            return;
        }

        string strFilename = @"C:\Bethesda Car Rental\Customers.crc";

        Customer cust = new Customer();

        cust.FullName = editor.txtFullName.Text;
        cust.Address = editor.txtAddress.Text;
        cust.City = editor.txtCity.Text;
        cust.State = editor.cbxStates.Text;
        cust.ZIPCode = editor.txtZIPCode.Text;
        lstCustomers.Add(editor.txtDrvLicNbr.Text, cust);

        FileStream bcrStream = new FileStream(strFilename,
                                              FileMode.Create,
                                              FileAccess.Write,
                                              FileShare.Write);
        BinaryFormatter bcrBinary = new BinaryFormatter();
        bcrBinary.Serialize(bcrStream, lstCustomers);
        bcrStream.Close();

        ShowCustomers();
    }
}

Display the Employees form and double-click an unoccupied area of its body

Change the file as follows:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;

namespace BethesdaCarRental1a
{
    public partial class Employees : Form
    {
        SortedDictionary<string, Employee> lstEmployees;

        public Employees()
        {
            InitializeComponent();
        }

        internal void ShowEmployees()
        {
        }

        private void Employees_Load(object sender, EventArgs e)
        {
            lstEmployees = new SortedDictionary<string, Employee>();
            BinaryFormatter bfmEmployees = new BinaryFormatter();

            // This is the file that holds the list of parts
            string strFilename = @"C:\Bethesda Car Rental\Employees.cre";

            if (File.Exists(strFilename))
            {
                FileStream stmEmployees = new FileStream(strFilename,
                                                         FileMode.Open,
                                                         FileAccess.Read,
                                                         FileShare.Read);

                try
                {
                    // Retrieve the list of employees from file
                    lstEmployees =
			(SortedDictionary<string,
					 Employee>)
				bfmEmployees.Deserialize(stmEmployees);
                }
                finally
                {
                    stmEmployees.Close();
                }
            }

            ShowEmployees();
        }
    }
}

Return to the Employees form and double-click the New Employee button

Implement its event as follows:

private void btnNewEmployee_Click(object sender, EventArgs e)
{
    EmployeeEditor editor = new EmployeeEditor();
    Directory.CreateDirectory(@"C:\Bethesda Car Rental");

    if (editor.ShowDialog() == DialogResult.OK)
    {
        if (editor.txtEmployeeNumber.Text == "")
        {
            MessageBox.Show("You must provide an employee number");
            return;
        }

        if (editor.txtLastName.Text == "")
        {
            MessageBox.Show("You must provide the employee's last name");
            return;
        }

        string strFilename = @"C:\Bethesda Car Rental\Employees.cre";

        Employee empl = new Employee();

        empl.FirstName = editor.txtFirstName.Text;
        empl.LastName = editor.txtLastName.Text;
        empl.Title = editor.txtTitle.Text;
        empl.HourlySalary = double.Parse(editor.txtHourlySalary.Text);
        lstEmployees.Add(editor.txtEmployeeNumber.Text, empl);

        FileStream bcrStream = new FileStream(strFilename,
                                              FileMode.Create,
                                              FileAccess.Write,
                                              FileShare.Write);
        BinaryFormatter bcrBinary = new BinaryFormatter();
        bcrBinary.Serialize(bcrStream, lstEmployees);
        bcrStream.Close();

        ShowEmployees();
    }
}

Save all

Accessing the Items of a Dictionary-Type of List

Although, or because, the key and value are distinct, to consider their combination as a single object, if you are using either the System.Collections.Hasthtable or the System.Collections.SortedList class, the .NET Framework provides the DictionaryEntry structure. To access an item, you can use the foreach loop to visit each item.

To support the foreach loop, the System.Collections.Hashtable and the System.Collections.SortedList classes implement the IEnumerable.GetEnumerator() method. In this case, the item is of type DictionaryEntry: it contains a Key and a Value in combination.

Practical Learning: Enumerating the Members of a Collection

Display the Order Processing form
On the form, click the Driver's Lic # text box
In the Properties window, click the Events button and, in the Events section, double-click Leave

Implement the event as follows:

private void txtDrvLicNumber_Leave(object sender, EventArgs e)
{
    Customer renter = null;
    string strDrvLicNumber = txtDrvLicNumber.Text;

    if (strDrvLicNumber.Length == 0)
    {
        MessageBox.Show("You must enter the renter's " +
                        "driver's license number");
        txtDrvLicNumber.Focus();
        return;
    }

    Dictionary<string, Customer>  lstCustomers =
                new Dictionary<string, Customer>();
    BinaryFormatter bfmCustomers = new BinaryFormatter();

    string strFilename = @"C:\Bethesda Car Rental\Customers.crc";

    if (File.Exists(strFilename))
    {
         FileStream stmCustomers = new FileStream(strFilename,
                                                  FileMode.Open,
                                                  FileAccess.Read,
                                                  FileShare.Read);

        try
        {
            // Retrieve the list of customers
            lstCustomers =
                        (Dictionary<string, Customer>)
                            bfmCustomers.Deserialize(stmCustomers);
            if (lstCustomers.ContainsKey(strDrvLicNumber) == true)
            {
                foreach (KeyValuePair<string, Customer> cust in lstCustomers)
                {
		    if (cust.Key == strDrvLicNumber)
                    {
                        renter = cust.Value;
                        txtCustomerName.Text = renter.FullName;
                        txtCustomerAddress.Text = renter.Address;
                        txtCustomerCity.Text = renter.City;
                        cbxCustomerStates.Text = renter.State;
                        txtCustomerZIPCode.Text = renter.ZIPCode;
                    }
		}
            }
            else
            {
                txtCustomerName.Text = "";
                txtCustomerAddress.Text = "";
                txtCustomerCity.Text = "";
                cbxCustomerStates.Text = "";
                txtCustomerZIPCode.Text = "";
                MessageBox.Show("There is no customer with that driver's " +
                                "license number in our database");
                return;
            }
        }
        finally
        {
            stmCustomers.Close();
        }
    }
}

Access the Employees.cs file and implement the ShowEmployees() method as follows:

internal void ShowEmployees()
{
    if( lstEmployees.Count == 0)
        return;

    // Before displaying the employees, empty the list view
    lvwEmployees.Items.Clear();
    // This variable will allow us to identify the odd and even indexes
    int i = 1;

    // Use the KeyValuePair class to visit each key/value item
    foreach(KeyValuePair<string, Employee> kvp in lstEmployees )
    {
        ListViewItem lviEmployee = new ListViewItem(kvp.Key);

        Employee empl = kvp.Value;

        lviEmployee.SubItems.Add(empl.FirstName);
        lviEmployee.SubItems.Add(empl.LastName);
        lviEmployee.SubItems.Add(empl.FullName);
        lviEmployee.SubItems.Add(empl.Title);
        lviEmployee.SubItems.Add(empl.HourlySalary.ToString("F"));

        if( i % 2 == 0 )
        {
            lviEmployee.BackColor = Color.FromArgb(255, 128, 0);
            lviEmployee.ForeColor = Color.White;
        }
        else
        {
            lviEmployee.BackColor = Color.FromArgb(128, 64, 64);
            lviEmployee.ForeColor = Color.White;
        }

        lvwEmployees.Items.Add(lviEmployee);

        i++;
    }
}

Access the Customers.cs file and implement the ShowEmployees() method as follows:

internal void ShowCustomers()
{
    if (lstCustomers.Count == 0)
        return;

    lvwCustomers.Items.Clear();
    int i = 1;

    foreach (KeyValuePair<string, Customer> kvp in lstCustomers)
    {
        ListViewItem lviCustomer = new ListViewItem(kvp.Key);

        Customer cust = kvp.Value;

        lviCustomer.SubItems.Add(cust.FullName);
        lviCustomer.SubItems.Add(cust.Address);
        lviCustomer.SubItems.Add(cust.City);
        lviCustomer.SubItems.Add(cust.State);
        lviCustomer.SubItems.Add(cust.ZIPCode);

        if (i % 2 == 0)
        {
            lviCustomer.BackColor = Color.Navy;
            lviCustomer.ForeColor = Color.White;
        }
        else
        {
            lviCustomer.BackColor = Color.Blue;
            lviCustomer.ForeColor = Color.White;
        }

        lvwCustomers.Items.Add(lviCustomer);

        i++;
    }
}

Execute the application
Click the Cars button and create the cars
Close the Car Editor form

Click the Customers button then click the New Customer button continually and create a few customers as follows:

Driver's Lic. #	State	Full Name	Address	City	ZIP Code
M-505-862-575	MD	Lynda Melman	4277 Jamison Avenue	Silver Spring	20904
379-82-7397	DC	John Villard	108 Hacken Rd NE	Washington	20012
J-938-928-274	MD	Chris Young	8522 Aulage Street	Rockville	20852
497-22-0614	PA	Pamela Ulmreck	12075 Famina Rd	Blain	17006
922-71-8395	VA	Helene Kapsco	806 Hyena Drive	Alexandria	22231
C-374-830-422	MD	Hermine Crasson	6255 Old Georgia Ave	Silver Spring	20910
836-55-2279	NY	Alan Pastore	4228 Talion Street	Amherst	14228
397-59-7487	TN	Phillis Buster	724 Cranston Circle	Knoxville	37919
115-80-2957	FL	Elmus Krazucki	808 Rasters Ave	Orlando	32810
294-90-7744	VA	Helena Weniack	10448 Great Pollard Hwy	Arlington	22232

Close the Customers form
On the Central form, click the Employees button

Create a few employees as follows:

Employee #	First Name	Last Name	Title	Hourly Salary
62-845	Patricia	Katts	General Manager	42.25
92-303	Henry	Larson	Sales Representative	12.50
25-947	Gertrude	Monay	Sales Representative	14.05
73-947	Helene	Sandt	Intern	8.85
40-508	Melanie	Karron	Sales Representative	12.75
22-580	Ernest	Chisen	Sales Manager	22.95
20-308	Melissa	Roberts	Administrative Assistant	15.45

Notice that the list of employees is automatically sorted based on the employees numbers.
Close the forms and return to your programming environment

The Keys and the Values of a Collection

After adding one or more items to the list, they are stored in two collections. The keys are stored in a collection represented by a property named Keys. The values are stored in the Values property. In the System.Collections classes, the Keys and the Values properties are of type ICollection.

Practical Learning: Using the Keys of a Collection

Display the Order Processing form and double-click the New Rental Order/Reset button

Implement the event as follows:

private void btnNewRentalOrder_Click(object sender, EventArgs e)
{
    txtEmployeeNumber.Text = "";
    txtEmployeeName.Text = "";
    txtDrvLicNumber.Text = "";
    txtCustomerName.Text = "";
    txtCustomerAddress.Text = "";
    txtCustomerCity.Text = "";
    cbxCustomerStates.Text = "";
    txtCustomerZIPCode.Text = "";
    txtTagNumber.Text = "";
    cbxCarConditions.Text = "";
    txtMake.Text = "";
    txtModel.Text = "";
    txtCarYear.Text = "";
    cbxTankLevels.Text = "Empty";
    txtMileageStart.Text = "0";
    txtMileageEnd.Text = "0";
    dtpStartDate.Value = DateTime.Today;
    dtpEndDate.Value = DateTime.Today;
    txtDays.Text = "";
    cbxOrderStatus.Text = "";
    txtRateApplied.Text = "0.00";
    txtSubTotal.Text = "0.00";
    txtTaxRate.Text = "7.75";
    txtTaxAmount.Text = "0.00";
    txtOrderTotal.Text = "0.00";

    BinaryFormatter bfmRentalOrders = new BinaryFormatter();

    string strFilename = @"C:\Bethesda Car Rental\RentalOrders.cro";

    if (File.Exists(strFilename))
    {
        FileStream stmRentalOrders = new FileStream(strFilename,
                                                    FileMode.Open,
                                                    FileAccess.Read,
                                                    FileShare.Read);

        try
        {
            lstRentalOrders =
                (SortedList<int, RentalOrder>)
                    bfmRentalOrders.Deserialize(stmRentalOrders);
            ReceiptNumber =
		lstRentalOrders.Keys[lstRentalOrders.Count - 1] + 1;
        }
        finally
        {
            stmRentalOrders.Close();
        }
    }
    else
    {
        ReceiptNumber = 100001;
        lstRentalOrders = new SortedList<int, RentalOrder>();
    }

    txtReceiptNumber.Text = ReceiptNumber.ToString();
}

Return to the Order Processing form and double-click an unoccupied area of its body

Implement the Load event as follows:

private void OrderProcessing_Load(object sender, EventArgs e)
{
    btnNewRentalOrder_Click(sender, e);
}

Return to the Order Processing form

Checking the Existence of an Item

Locating an item in a dictionary type of list consists of looking for either a key, a value, or a combination of Key=Value. The Hashtable, the Dictionary, and the SortedList classes are equipped to handle these operations with little effort on your part. If you know the key of an item but want to find a value, you can use the indexed property because it produces it.

Checking the Existence of a Key

We have seen that the System.Collections.Hashtable.Contains() and the System.Collections.SortedList.Contains() methods allow you to find out whether a collection contains a certain specific key. An alternative is to call a method named ContainsKey.

The syntax of the System.Collections.Hashtable.ContainsKey() and the System.Collections.SortedList.ContainsKey() method is:

public virtual bool ContainsKey(object key);

The syntax of the System.Collections.Generic.Dictionary.ContainsKey() and the System.Collections.Generic.SortedList.ContainsKey() method is:

public bool ContainsKey(TKey key);

Practical Learning: Checking the Existence of a Key

On the Order Processing form, double-click the Save button and implement its event as follows:

private void btnSave_Click(object sender, EventArgs e)
{
    if (txtReceiptNumber.Text == "")
    {
        MessageBox.Show("The receipt number is missing");
        return;
    }

    // Don't save this rental order if we don't
    // know who processed it
    if (txtEmployeeNumber.Text == "")
    {
        MessageBox.Show("You must enter the employee number of the " +
                        "clerk who processed this order.");
        return;
    }

    // Don't save this rental order if we don't
    // know who is renting the car
    if (txtDrvLicNumber.Text == "")
    {
        MessageBox.Show("You must specify the driver's license number " +
                        "of the customer who is renting the car");
        return;
    }

    // Don't save the rental order if we don't
    // know what car is being rented
    if (txtTagNumber.Text == "")
    {
        MessageBox.Show("You must enter the tag number " +
                        "of the car that is being rented");
        return;
    }

    // Create a rental order based on the information on the form
    RentalOrder CurrentOrder = new RentalOrder();

    CurrentOrder.EmployeeNumber = txtEmployeeNumber.Text;
    CurrentOrder.OrderStatus = cbxOrderStatus.Text;
    CurrentOrder.CarTagNumber = txtTagNumber.Text;
    CurrentOrder.CustomerDrvLicNbr = txtDrvLicNumber.Text;
    CurrentOrder.CustomerName = txtCustomerName.Text;
    CurrentOrder.CustomerAddress = txtCustomerAddress.Text;
    CurrentOrder.CustomerCity = txtCustomerCity.Text;
    CurrentOrder.CustomerState = cbxCustomerStates.Text;
    CurrentOrder.CustomerZIPCode = txtCustomerZIPCode.Text;
    CurrentOrder.CarCondition = cbxCarConditions.Text;
    CurrentOrder.TankLevel = cbxTankLevels.Text;

    try
    {
        CurrentOrder.MileageStart = int.Parse(txtMileageStart.Text);
    }
    catch (FormatException)
    {
        MessageBox.Show("Invalid mileage start value");
    }

    try
    {
        CurrentOrder.MileageEnd = int.Parse(txtMileageEnd.Text);
    }
    catch (FormatException)
    {
        MessageBox.Show("Invalid mileage end value");
    }

    try
    {
        CurrentOrder.DateStart = dtpStartDate.Value;
    }
    catch (FormatException)
    {
        MessageBox.Show("Invalid start date");
    }

            try
            {
                CurrentOrder.DateEnd = dtpEndDate.Value;
            }
            catch (FormatException)
            {
                MessageBox.Show("Invalid end date");
            }

            try
            {
                CurrentOrder.Days = int.Parse(txtDays.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("Invalid number of days");
            }

            try
            {
                CurrentOrder.RateApplied = double.Parse(txtRateApplied.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("Invalid rate value");
            }

            CurrentOrder.SubTotal = double.Parse(txtSubTotal.Text);

            try
            {
                CurrentOrder.TaxRate = double.Parse(txtTaxRate.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("Inavlid tax rate");
            }

            CurrentOrder.TaxAmount = double.Parse(txtTaxAmount.Text);
            CurrentOrder.OrderTotal = double.Parse(txtOrderTotal.Text);
            // The rental order is ready

            // Get the receipt number from its text box
            try
            {
                ReceiptNumber = int.Parse(txtReceiptNumber.Text);
            }
            catch (FormatException)
            {
                MessageBox.Show("You must provide a receipt number");
            }

            // Get the list of rental orders and 
            // check if there is already one with the current receipt number
            // If there is already a receipt number like that...
            if (lstRentalOrders.ContainsKey(ReceiptNumber) == true)
            {
                // Simply update its value
                lstRentalOrders[ReceiptNumber] = CurrentOrder;
            }
            else
            {
                // If there is no order with that receipt,
                // then create a new rental order
                lstRentalOrders.Add(ReceiptNumber, CurrentOrder);
            }
    
    // The list of rental orders
    string strFilename = @"C:\Bethesda Car Rental\RentalOrders.cro";
    FileStream bcrStream = new FileStream(strFilename,
                                          FileMode.Create,
                                          FileAccess.Write,
                                          FileShare.Write);
    BinaryFormatter bcrBinary = new BinaryFormatter();

    try
    {
        bcrBinary.Serialize(bcrStream, lstRentalOrders);
    }
    finally
    {
        bcrStream.Close();
    }
}

Save the file

Checking the Existence of a Value

To find out whether a particular value exists in the list, you can call the ContainsValue() method. The syntax of the System.Collections.Hashtable.ContainsValue() and the System.Collections.SortedList.ContainsValue() method is::

public virtual bool ContainsValue(object key);

The syntax of the System.Collections.Generic.Dictionary.ContainsValue() and the System.Collections.Generic.SortedList.ContainsValue() method is:

public bool ContainsValue(TKey key);

Practical Learning: Getting the Value of a Key

On the Order Processing form, click the Employee Number text box

In the Events section of the Properties window, double-click Leave and implement the event as follows:

private void txtEmployeeNumber_Leave(object sender, EventArgs e)
{
    Employee clerk;
    string strEmployeeNumber = txtEmployeeNumber.Text;

    if (strEmployeeNumber.Length == 0)
    {
        MessageBox.Show("You must enter the employee's number");
                txtEmployeeNumber.Focus();
                return;
    }

    SortedDictionary<string, Employee> lstEmployees =
                new SortedDictionary<string, Employee>();
    BinaryFormatter bfmEmployees = new BinaryFormatter();

    string strFilename = @"C:\Bethesda Car Rental\Employees.cre";

    if (File.Exists(strFilename))
    {
        FileStream stmEmployees = new FileStream(strFilename,
                                                 FileMode.Open,
                                                 FileAccess.Read,
                                                 FileShare.Read);
        try
        {
           // Retrieve the list of employees
            lstEmployees =
                        (SortedDictionary<string, Employee>)
                            bfmEmployees.Deserialize(stmEmployees);
            if (lstEmployees.TryGetValue(strEmployeeNumber, out clerk))
            {
                txtEmployeeName.Text = clerk.FullName;
            }
            else
            {
                txtEmployeeName.Text = "";
                MessageBox.Show("There is no employee with that number");
                return;
            }
        }
        finally
        {
            stmEmployees.Close();
        }
    }
}

Return to the Order Processing form and click the Tag Number text box

In the Events section of the Properties window, double-click Leave and implement the event as follows:

private void txtTagNumber_Leave(object sender, EventArgs e)
{
    Car selected;
    string strTagNumber = txtTagNumber.Text;

    if (strTagNumber.Length == 0)
    {
        MessageBox.Show("You must enter the car's tag number");
        txtTagNumber.Focus();
        return;
    }

    Dictionary<string, Car> lstCars =
                new Dictionary<string, Car>();
    BinaryFormatter bfmCars = new BinaryFormatter();

    string strFilename = @"C:\Bethesda Car Rental\Cars.crs";

    if (File.Exists(strFilename))
    {
        FileStream stmCars = new FileStream(strFilename,
                                            FileMode.Open,
                                            FileAccess.Read,
                                            FileShare.Read);
        try
        {
            // Retrieve the list of employees from file
            lstCars =
                (Dictionary<string, Car>)
                        bfmCars.Deserialize(stmCars);
            if (lstCars.TryGetValue(strTagNumber, out selected))
            {
                txtMake.Text = selected.Make;
                txtModel.Text = selected.Model;
                txtCarYear.Text = selected.Year.ToString();
            }
            else
            {
                txtMake.Text = "";
                txtModel.Text = "";
                txtCarYear.Text = "";
                MessageBox.Show("There is no car with that tag " +
                                "number in our database");
                return;
            }
        }
        finally
        {
            stmCars.Close();
        }
    }
}

Display the Order Processing form and double-click the Open button

Implement its event as follows:

private void btnOpen_Click(object sender, EventArgs e)
{
    RentalOrder order = null;

    if (txtReceiptNumber.Text == "")
    {
        MessageBox.Show("You must enter a receipt number");
        return;
    }

    ReceiptNumber = int.Parse( txtReceiptNumber.Text);

    if (lstRentalOrders.TryGetValue(ReceiptNumber, out order))
    {
        txtEmployeeNumber.Text = order.EmployeeNumber;
        txtEmployeeNumber_Leave(sender, e);
        cbxOrderStatus.Text = order.OrderStatus;
        txtTagNumber.Text = order.CarTagNumber;
        txtTagNumber_Leave(sender, e);
        txtDrvLicNumber.Text = order.CustomerDrvLicNbr;
        txtCustomerName.Text = order.CustomerName;
        txtCustomerAddress.Text = order.CustomerAddress;
        txtCustomerCity.Text = order.CustomerCity;
        cbxCustomerStates.Text = order.CustomerState;
        txtCustomerZIPCode.Text = order.CustomerZIPCode;
        cbxCarConditions.Text = order.CarCondition;
        cbxTankLevels.Text = order.TankLevel;
        txtMileageStart.Text = order.MileageStart.ToString();
        txtMileageEnd.Text = order.MileageEnd.ToString();
        dtpStartDate.Value = order.DateStart;
        dtpEndDate.Value = order.DateEnd;
        txtDays.Text = order.Days.ToString();
        txtRateApplied.Text = order.RateApplied.ToString("F");
        txtSubTotal.Text = order.SubTotal.ToString("F");
        txtTaxRate.Text = order.TaxRate.ToString("F");
        txtTaxAmount.Text = order.TaxAmount.ToString("F");
        txtOrderTotal.Text = order.OrderTotal.ToString("F");
    }
    else
    {
        MessageBox.Show("There is no rental order with that receipt number");
        return;
    }
}

Return to the Order Processing form

Double-click the Close button and implement the event as follows:

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

Execute the application
Create a few rental orders and print them
Close the forms and return to your programming environment
Execute the application again
Open a previously created order to simulate a customer returning a car and change some values on the form such as the return date, the mileage end, and the order status
Also click the Calculate button to get the final evaluation
Print the rental orders
Close the forms and return to your programming environment

Download


Home	Copyright © 2007-2013, FunctionX