Database Application: Fun Department Store

	Database Application: Fun Department Store

Description

As its name indicates, a table adapter is an object that gives access to a database's table. This is a review of the automatically generated data set and its data tables created by the Data Source Configuration Wizard of Microsoft Visual Studio 2008. To illustrate the features, we create an application for a department store.

The clothes (manufacturers, names, sizes, categories, and prices used in the database of this application were retrieved/taken from the Lord & Taylor and the Ann Taylor web sites (http://www.lordandtaylor.com and http://www.anntaylor.com) (This just in case you want to know; this is not an advertisement) during the month of November 2009 (most, if not all, of the items without a manufacturer are from Ann Taylor).

Practical Learning: Introducing Data Sets

Open the FunDS1.htm file
Select its content and copy it
Start Microsoft SQL Server and connect to the server
Create a Query window and paste the code in it
To create the database, press F5
Start Microsoft Visual Studio and create a Windows Application named FunDepartmentStore1
In the Solution Explorer, right-click Form1.cs and click Rename
Type Central.vb and press Enter
From the Components section of the Toolbox, click Timer and click the form

Design the form as follows:

Control	Text	Name
Button	Process a Customer Order	btnProcessOrder
Button	Create a New Store Item	btnCreateStoreItem
Button	View Current Inventory	btnCurrentInventory
Button	Manage a Store Items	btnManageStoreItem
Button	Close	btnClose

To add a new form, on the menu, click Project -> Add Windows Form...
Set the Name to ShoppingSession and click Add

Design the form as follows:

Control

Text

Name

Other Properties

Form

Fun Department Store - Shopping Session

ShowInTaskbar: False
StartPosition: CenterScreen

Panel

BorderStyle: Fixed3D

Label

Item #

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

Label

Item Name/Description

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

Label

Size

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

Label

Unit Price

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

TextBox

txtItemNumber

Font: Times New Roman, 20.25pt
TextAlign: Center

TextBox

txtItemName

Font: Times New Roman, 20.25pt

TextBox

txtItemSize

Font: Times New Roman, 20.25pt

TextBox

txtUnitPrice

Font: Times New Roman, 20.25pt
TextAlign: Right

ListView

lvwShoppingSession

Anchor: Top, Bottom, Left, Right
Font: Times New Roman, 20.25pt
FullRowSelect: True
GridLines: True
View: Details

Columns

(Name)	Text	TextAlign	Width
colItemNumber	Item #		100
colItemName	Item Name/Description		446
colItemSize	Size	Center	100
colUnitPrice	Unit Price	Right	124

Label

Type of Payment:

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

ComboBox

cbxCurrencyType

Font: Times New Roman, 20.25pt, style=Bold
Items: Cash
          Check
          Visa
          Master Card
          Store Card

Label

Order Total:

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

TextBox

txtOrderTotal

Anchor: Bottom, Right
Font: Times New Roman, 20.25pt, style=Bold
Text: 0.00
TextAlign: Right

Label

Order Time:

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

Label

Order Date:

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

Label

Amount Tended:

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

TextBox

txtAmountTended

Anchor: Bottom, Right
Font: Times New Roman, 20.25pt, style=Bold
Text: 0.00
TextAlign: Right

Button

btnSubmitOrder

Anchor: Bottom, Left, Right
Font: Times New Roman, 20.25pt, style=Bold

Label

Change:

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

TextBox

txtChange

Anchor: Bottom, Right
Font: Times New Roman, 20.25pt, style=Bold
Text: 0.00
TextAlign: Right

Label

Receipt #:

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

TextBox

txtReceiptNumber

Anchor: Bottom, Right
Font: Times New Roman, 20.25pt, style=Bold

Button

btnCancelOrder

Anchor: Bottom, Left, Right
Font: Times New Roman, 20.25pt, style=Bold

Panel

BorderStyle: Fixed3D

Label

lblDate

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

Label

lblTime

Font: Times New Roman, 20.25pt, style=Bold
ForeColor: Blue

Button

btnClose

Anchor: Bottom, Left, Right
Font: Times New Roman, 20.25pt, style=Bold

Timer

tmrDateTime

Enabled: True

Double-click the timer

Implement its event as follows:

Private Sub tmrDateTime_Tick(ByVal sender As System.Object, _
                                 ByVal e As System.EventArgs) _
                                 Handles tmrDateTime.Tick
        lblDate.Text = DateTime.Today.ToLongDateString()
        lblTime.Text = DateTime.Now.ToLongTimeString()
End Sub

Save All

Practical Learning: Generating a Table Adapter

On the main menu, click Data -> Add New Data Source...
On the first page of the wizard, make sure Database is selected and click Next
In the second page of the wizard, click New Connection...
In the Server Name combo box, select the server or type (local)
In the Select or Enter a Database Name combo box, select FunDS1
Click Test Connection
Click OK twice
On the Data Source Configuration Wizard, make sure the new connection is selected
Click the + button of Connection String
Click Next
Change the connection string to CstrFunDS and click Next
Click the check box of Tables (to select all tables)
Change the name of the data set to DsFunDS
Click Finish
In the Solution Explorer, double-click dsFunDS.Designer.cs to open and view the file
Press Ctrl + F5 to execute
After viewing the main form, close it
Display the ShoppingSession form
In the top section of the Toolbox, click dsFunDS and click the form
In the top section of the Toolbox, click CustomersOrdersTableAdapter and click the form
In the Properties window, change its name to TaCustomersOrders
In the top section of the Toolbox, click ReceiptsSummariesTableAdapter and click the form
In the Properties window, change its name to TaReceiptsSummaries
In the top section of the Toolbox, click StoreItemsTableAdapter and click the form
In the Properties window, change its name to TaStoreItems
Save the form

Practical Learning: Getting the Records

To add another form, on the main menu, click Project -> Add Windows Form
Set the Name to CurrentStoreInventory and click Add
In the top section of the Toolbox, click DsFunDS and click the form
In the top section of the Toolbox, click StoreItemsTableAdapter and click the form
In the Properties window, change its name to TaStoreItems

Design the form as follows:

Control

Text

Name

Other Properties

ListView

lvwStoreItems

FullRowSelect: True
GridLines: True
View: Details

Columns

(Name)	Text	TextAlign	Width
colItemNumber	Item #		100
colManufacturer	Manufacturer		80
colCategory	Category
colSCategoryub	Sub-Category		80
colItemName	Item Name/Description		200
colItemSize	Size	Center	100
colUnitPrice	Unit Price	Right

Button

Show Store Items Inventory

btnShowCurrentInventory

Double-click the Show Store Items Inventory button and implement its Click event as follows:

''' <summary>
''' When the Show Current Inventory button is clicked, the form shows
''' a list of the items that have been added to the Store Items table
''' </summary>
''' <param name="sender"></param>
''' <param name="e"></param>
''' <remarks></remarks>
Private Sub btnShowCurrentInventory_Click(ByVal sender As System.Object, _
                                          ByVal e As System.EventArgs) _
                                          Handles btnShowCurrentInventory.Click
    Dim i As Integer

    For i = 0 To TaStoreItems.GetData().Rows.Count - 1
            Dim RcdStoreItem As DataRow = TaStoreItems.GetData().Rows(i)

            Dim LviStoreItem As ListViewItem = New ListViewItem(CStr((i + 1)))

            LviStoreItem.SubItems.Add(CStr(RcdStoreItem("ItemNumber")))

            If IsDBNull(RcdStoreItem("Manufacturer")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("Manufacturer")))
            End If

            If IsDBNull(RcdStoreItem("Category")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("Category")))
            End If

            If IsDBNull(RcdStoreItem("SubCategory")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("SubCategory")))
            End If

            If IsDBNull(RcdStoreItem("ItemName")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("ItemName")))
            End If

            If IsDBNull(RcdStoreItem("ItemSize")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("ItemSize")))
            End If

            If IsDBNull(RcdStoreItem("UnitPrice")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CDbl(FormatNumber(RcdStoreItem("UnitPrice"))))
            End If

            If IsDBNull(RcdStoreItem("SaleStatus")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("SaleStatus")))
            End If

            lvwStoreItems.Items.Add(LviStoreItem)
    Next
End Sub

Save all
Show the Central form
Double-click the View Current Inventory

Implement its Click event as follows:

Private Sub btnCurrentInventory_Click(ByVal sender As System.Object, _
                                          ByVal e As System.EventArgs) _
                                          Handles btnCurrentInventory.Click
        Dim csi As CurrentStoreInventory = New CurrentStoreInventory()
        csi.ShowDialog()
End Sub

Press Ctrl + F5 to execute
Open the Current Inventory form
Click the Show Store Items Inventory button
Close the forms and return to your programming environment

Department Store - Store Inventory

Practical Learning: Locating a Record Based on a Column Name

In the Solution Explorer, right-click the ShoppingSession.vb and click View Code

Import the System.Data.SqlClient namespace and declare two global variables as follows:

Imports System.Data.SqlClient

Public Class ShoppingSession
    ' The ReceiptNumber variable will represent the receipt number
    Dim ReceiptNumber As Integer
    ' This variable will represent the total value of the shopping  
    Dim TotalOrder As Double

    . . .
    
End Class

In the Class Name combo box, select the btnCancelOrder
In the Method Name combo box, select Click

Implement its event as follows:

Private Sub btnCancelOrder_Click(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles btnCancelOrder.Click
        REM First reset the form
        TotalOrder = 0.0
        txtItemNumber.Text = ""
        txtItemName.Text = ""
        txtUnitPrice.Text = "0.00"
        lvwShoppingSession.Items.Clear()
        txtOrderTotal.Text = "0.00"
        txtAmountTended.Text = "0.00"
        txtChange.Text = "0.00"

        If TaCustomersOrders.GetData().Rows.Count > 0 Then
            For Each RcdCustomerOrder As DataRow In TaCustomersOrders.GetData().Rows
                ReceiptNumber = CInt(CStr(RcdCustomerOrder("ReceiptNumber"))) + 1
            Next
        End If

        txtReceiptNumber.Text = CStr(ReceiptNumber)
End Sub

In the Class Name combo box, select (ShoppingSession Events)
In the Method Name combo box, select Load

Implement its event as follows:

Private Sub ShoppingSession_Load(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles Me.Load
        TotalOrder = 0.0
        ReceiptNumber = 100000
        btnCancelOrder_Click(sender, e)
End Sub

Save all

Practical Learning: Finding a Record

The ShoppingSession form (the ShoppingSession.vb (Design) tab) should be displaying.
In the Class name combo box, select txtItemNumber
In the Method Name combo box, select Leave

Implement the event as follows:

Private Sub txtItemNumber_Leave(ByVal sender As Object, _
                                    ByVal e As System.EventArgs) _
                                    Handles txtItemNumber.Leave
        Dim unitPrice As Double = 0.0

        If txtItemNumber.Text.Equals("") Then
            Exit Sub
        End If

        Try
            Dim rcdStoreItem As DataRow = TaStoreItems.GetData().Rows.Find(txtItemNumber.Text)

            If IsDBNull(rcdStoreItem("ItemName")) Then
                txtItemName.Text = ""
            Else
                txtItemName.Text = CStr(rcdStoreItem("ItemName"))
            End If

            If IsDBNull(rcdStoreItem("ItemSize")) Then
                txtItemSize.Text = ""
            Else
                txtItemSize.Text = CStr(rcdStoreItem("ItemSize"))
            End If

            If IsDBNull(rcdStoreItem("UnitPrice")) Then
                txtUnitPrice.Text = "0.00"
            Else
                unitPrice = CDbl(CStr(rcdStoreItem("UnitPrice")))

                TotalOrder = TotalOrder + unitPrice
                txtUnitPrice.Text = CStr(unitPrice)
            End If

            Dim LviStoreItem As ListViewItem = New ListViewItem(txtItemNumber.Text)

            LviStoreItem.SubItems.Add(txtItemName.Text)
            LviStoreItem.SubItems.Add(txtItemSize.Text)
            LviStoreItem.SubItems.Add(FormatNumber(unitPrice))
            lvwShoppingSession.Items.Add(LviStoreItem)

            txtOrderTotal.Text = FormatNumber(TotalOrder)

            txtItemNumber.Text = ""
            txtItemName.Text = ""
            txtItemSize.Text = ""
            txtUnitPrice.Text = "0.00"
            txtItemNumber.Focus()
        Catch nre As NullReferenceException
            MsgBox("There is no store item with that number")
        Catch ioore As IndexOutOfRangeException
            MsgBox("There is no store item with that number")
        End Try
End Sub

In the Class Name combo box, select txtAmountTended
In the Method Name combo box, select Leave

Implement the event as follows:

Private Sub txtAmountTended_Leave(ByVal sender As Object, _
                                      ByVal e As System.EventArgs) _
                                      Handles txtAmountTended.Leave
        Dim totalOrder As Double
        Dim amountTended As Double
        Dim change As Double

        Try
            totalOrder = CDbl(txtOrderTotal.Text)
            amountTended = CDbl(txtAmountTended.Text)
            change = amountTended - totalOrder

            txtChange.Text = FormatNumber(change)
            btnSubmitOrder.Focus()
        Catch fe As FormatException
            MsgBox("Invalid Value!")
        End Try
End Sub

Return to the Central form
Double-click the Process Customer Order

Implement its Click event as follows:

Private Sub btnProcessOrder_Click(ByVal sender As Object, _
                                      ByVal e As System.EventArgs) _
                                      Handles btnProcessOrder.Click
        Dim shop As ShoppingSession = New ShoppingSession()
        shop.ShowDialog()
End Sub

To create a new form, on the main menu, click Project -> Add Windows Form...
Set the Name to ManageStoreItem and click Add
In the top section of the Toolbox, click dsFunDS and click the form
In the top section of the Toolbox, click StoreItemsTableAdapter and click the form
In the Properties window, change its name to TaStoreItems

Design the form as follows:

Control	Text	Name	Other Properties
Label	Item #:
TextBox		btnItemNumber
Button	Find	btnFind
Label	Manufacturer
TextBox		Manufacturer
Label	Category:
ComboBox		cbxCategories	Items: Men Girls Boys Babies Women Other
Label	Sub-Category:
ComboBox		cbxSubCategories	Items: Skirts Pants Shirts Shoes Beauty Dresses Clothing Sweater Watches Handbags Miscellaneous
Label	Item Name:
TextBox		btnItemName
Label	Size:
TextBox		btnItemSize
Label	Unit Price:
TextBox		btnUnitPrice	Text: 0.00 TextAlign: Right
Label	Sale Status:
ComboBox		cbxSaleStatus	Items: Available Sold Processing Other
Button	Reset	btnReset
Button	Submit Changes	btnSubmitChanges
Button	Delete this Item	btnDeleteStoreItem
Button	Close	btnClose

Double-click the Reset button

Implement the event as follows:

Private Sub btnReset_Click(ByVal sender As System.Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnReset.Click
        txtItemNumber.Text = ""
        txtManufacturer.Text = ""
        cbxCategories.Text = "Women"
        txtItemName.Text = ""
        txtItemSize.Text = ""
        txtUnitPrice.Text = "0.00"
        txtManufacturer.Focus()
End Sub

In the Class Name combo box, select btnFind
In the Method Name combo box, select Click

Implement its event as follows:

Private Sub btnFind_Click(ByVal sender As Object, _
                              ByVal e As System.EventArgs) _
                              Handles btnFind.Click
        Dim unitPrice As Double = 0.0

        If txtItemNumber.Text = "" Then
            Exit Sub
        End If
        Try
            Dim rcdStoreItem As DataRow = _
                TaStoreItems.GetData().Rows.Find(txtItemNumber.Text)

            If IsDBNull(rcdStoreItem("ItemName")) Then
                txtItemName.Text = ""
            Else
                txtItemName.Text = CStr(rcdStoreItem("ItemName"))
            End If

            If IsDBNull(rcdStoreItem("Manufacturer")) Then
                txtManufacturer.Text = ""
            Else
                txtManufacturer.Text = CStr(rcdStoreItem("Manufacturer"))
            End If

            If IsDBNull(rcdStoreItem("Category")) Then
                cbxCategories.Text = ""
            Else
                cbxCategories.Text = CStr(rcdStoreItem("Category"))
            End If

            If IsDBNull(rcdStoreItem("SubCategory")) Then
                cbxSubCategories.Text = ""
            Else
                cbxSubCategories.Text = CStr(rcdStoreItem("SubCategory"))
            End If

            If IsDBNull(rcdStoreItem("itemName")) Then
                txtItemName.Text = ""
            Else
                txtItemName.Text = CStr(rcdStoreItem("itemName"))
            End If

            If IsDBNull(rcdStoreItem("ItemSize")) Then
                txtItemSize.Text = ""
            Else
                txtItemSize.Text = CStr(rcdStoreItem("ItemSize"))
            End If

            If IsDBNull(rcdStoreItem("UnitPrice")) Then
                txtUnitPrice.Text = "0.00"
            Else
                unitPrice = CDbl(CStr(rcdStoreItem("UnitPrice")))
                txtUnitPrice.Text = CStr(unitPrice)
            End If

            If IsDBNull(rcdStoreItem("SaleStatus")) Then
                cbxSaleStatus.Text = ""
            Else
                cbxSaleStatus.Text = CStr(rcdStoreItem("SaleStatus"))
            End If
        Catch nre As NullReferenceException
            MsgBox("There is no store item with that number")
            btnReset_Click(sender, e)
        Catch ioore As IndexOutOfRangeException
            MsgBox("There is no store item with that number")
            btnReset_Click(sender, e)
        End Try
End Sub

Display the Central form
Double-click the Manage Store Item

Implement the event as follows:

Private Sub btnManageStoreItem_Click(ByVal sender As Object, _
                                         ByVal e As System.EventArgs) _
                                         Handles btnManageStoreItem.Click
        Dim msi As ManageStoreItem = New ManageStoreItem()
        msi.ShowDialog()
End Sub

Press Ctrl + F5 to execute
Display the Manage Store Item form
In the Item # text box, enter 294725 and click Find
Enter 557504 and click Find
Close the forms and return to your programming environment
Save all

Practical Learning: Adding and/or Updating a Record

Display the Shopping Session form
Double-click the Submit Current Order button

Implement its event as follows:

Private Sub btnSubmitOrder_Click(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles btnSubmitOrder.Click
        Dim i As Integer
        If lvwShoppingSession.Items.Count = 0 Then
            MsgBox("There is no record to create.")
            Exit Sub
        End If

        REM Add the list of items to the CustomersOrders table
        Try
            For i = 0 To lvwShoppingSession.Items.Count - 1
                TaCustomersOrders.Insert(CStr(ReceiptNumber), _
                                         lblDate.Text, _
                                         lblTime.Text, _
                                         lvwShoppingSession.Items(i).Text, _
                                         lvwShoppingSession.Items(i).SubItems(1).Text, _
                                         lvwShoppingSession.Items(i).SubItems(2).Text, _
                                         CDec(lvwShoppingSession.Items(i).SubItems(3).Text))


                Dim RcdStoreItem As DataRow = _
                TaStoreItems.GetData().Rows.Find(lvwShoppingSession.Items(i).Text)
                RcdStoreItem("SaleStatus") = "Sold"
                TaStoreItems.Update(RcdStoreItem)
            Next

            REM Let the user know
            MsgBox("The customer order has been saved.")
        Catch ioore As IndexOutOfRangeException
            MsgBox("There is no store item with that number")
        End Try

        REM Create a record in the ReceiptSummaries table
        Try
            TaReceiptsSummaries.Insert(txtReceiptNumber.Text, _
                                       lblDate.Text, _
                                       lblTime.Text, _
                                       CDec(txtOrderTotal.Text), _
                                       cbxCurrencyType.Text, _
                                       CDec(txtAmountTended.Text), _
                                       CDec(txtChange.Text))

            REM Receipt the form
            btnCancelOrder_Click(sender, e)
        Catch ioore As IndexOutOfRangeException
            MsgBox("There is no store item with that number")
        End Try
End Sub

Press Ctrl + F5 to execute the application
Click Process a Customer Order
Create a customer order that uses

Item #: 952735
Change the Amount Tended to 500 and press Tab
Click Submit Current Order
Create another customer order that uses

Item #: 927940

Item #: 790064
Change the Amount Tended to 300 and press Tab
Click Submit Current Order
Create another customer order that uses

Item #: 290030

Item #: 790402

Item #: 729741

Item #: 297030
Change the Amount Tended to 300 and press Tab
Click Submit Current Order
Create another customer order that uses

Item #: 797140
Change the Amount Tended to 20 and press Tab
Click Submit Current Order
Close the forms and return to your programming environment
Display the Manage Store Item form
Double-click the Submit Changes button

Implement its Click event as follows:

Private Sub btnSubmitChanges_Click(ByVal sender As System.Object, _
                                       ByVal e As System.EventArgs) _
                                       Handles btnSubmitChanges.Click
        If txtItemNumber.Text.Length = 0 Then
            MsgBox("You must provide a (unique) item number.")
            Exit Sub
        End If

        If txtItemName.Text.Length = 0 Then
            MsgBox("You must provide a name for the item.")
            Exit Sub
        End If

        If txtUnitPrice.Text.Length = 0 Then
            MsgBox("You must provide a price for the item.")
            Exit Sub
        End If

        Try
            Dim rcdStoreItem As DataRow = _
		TaStoreItems.GetData().Rows.Find(txtItemNumber.Text)

            If txtManufacturer.Text.Length <> 0 Then
                rcdStoreItem("Manufacturer") = txtManufacturer.Text
            End If

            If cbxCategories.Text.Length <> 0 Then
                rcdStoreItem("Category") = cbxCategories.Text
            End If

            If cbxSubCategories.Text.Length <> 0 Then
                rcdStoreItem("SubCategory") = cbxSubCategories.Text
            End If

            rcdStoreItem("ItemName") = txtItemName.Text

            If txtItemSize.Text.Length <> 0 Then
                rcdStoreItem("ItemSize") = txtItemSize.Text
            End If

            rcdStoreItem("UnitPrice") = CStr(txtUnitPrice.Text)

            TaStoreItems.Update(rcdStoreItem)

            REM Let the user know
            MsgBox("The item has been updated")

            btnReset_Click(sender, e)
        Catch ioore As IndexOutOfRangeException
            MsgBox("There is no store item with that number")
        End Try
End Sub

Press Ctrl + F5 to execute the application
Click the Manage a Store Item button
Item the item number, enter 582604 and click Find

If the record is found, change the values as follows:

	Manufacturer	Delete
	Item Name	Sleeveless Sweater Dress
	Size	L
	Unit Price	125
	Sale Status	Available

Click Submit Changes
In the item number, enter 770240 and click Find

If the record is found, change the values as follows:

Manufacturer	Caparros
Sub Category	Shoes
Item Name	Peep-Toe Silk Stiletto Sandals
Size	7.5
Unit Price	65.00
Sale Status	Available

Click Submit Changes
Close the forms and return to your programming environment

Practical Learning: Creating a Record

Start Microsoft Visual Studio and open the FunDepartmentStore1 from the previous lesson
To create a new form, on the main menu, click Project -> Add Windows Form...
Set the Name to CreateStoreItem and click Add
In the top section of the Toolbox, click dsFunDS and click the form
In the top section of the Toolbox, click StoreItemsTableAdapter and click the form
In the Properties window, change its name to TaStoreItems

Design the form as follows:

Control	Text	Name	Other Properties
Label	Item #:
TextBox		txtItemNumber
Label	Manufacturer:
TextBox		txtManufacturer
Label	Category:
TextBox		cbxCategories	Items: Men Girls Boys Babies Women Other
Label	Sub-Category:
TextBox		cbxSubCategories	Items: Skirts Pants Shoes Shirts Beauty Dresses Clothing Sweater Watches Handbags Miscellaneous
Label	Item Name:
TextBox		btnItemName
Label	Size:
TextBox		btnItemSize
Label	Unit Price:
TextBox		btnUnitPrice	Text: 0.00 TextAlign: Right
Label	Sale Status:
ComboBox		cbxSaleStatus	Items: Available Sold Processing Other
Button	Reset	btnReset
Button	Create	btnCreate
Button	Close	btnClose

Double-click the Reset button

Implement the event as follows:

Private Sub btnReset_Click(ByVal sender As System.Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnReset.Click
        txtItemNumber.Text = "000000"

        txtManufacturer.Text = ""
        cbxCategories.Text = "Women"
        txtItemName.Text = ""
        txtSize.Text = ""
        txtUnitPrice.Text = "0.00"
        txtManufacturer.Focus()
End Sub

In the Class Name combo box, select (CreateStoreItem Events)
In the Method Name combo box, select Load

Implement the event as follows:

Private Sub CreateStoreItem_Load(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles Me.Load
        btnReset_Click(sender, e)
End Sub

In the Class Name combo box, select btnCreate
In the Method Name combo box, select Click

Implement the event as follows:

Private Sub btnCreate_Click(ByVal sender As Object, _
                                ByVal e As System.EventArgs) _
                                Handles btnCreate.Click
        If txtItemNumber.Text.Length = 0 Then
            MsgBox("You must provide a (unique) item number.")
            Exit Sub
        End If

        If txtItemName.Text.Length = 0 Then
            MsgBox("You must provide a name for the item.")
            Exit Sub
        End If

        If txtUnitPrice.Text.Length = 0 Then
            MsgBox("You must provide a price for the item.")
            Exit Sub
        End If

        REM Create a record in the ReceiptSummaries table
        Try
            Dim rcdStoreItems As DataRow = DsFunDS1.Tables("StoreItems").NewRow()

            rcdStoreItems("ItemNumber") = txtItemNumber.Text
            rcdStoreItems("Manufacturer") = txtManufacturer.Text
            rcdStoreItems("Category") = cbxCategories.Text
            rcdStoreItems("SubCategory") = cbxSubCategories.Text
            rcdStoreItems("ItemName") = txtItemName.Text
            rcdStoreItems("ItemSize") = txtSize.Text
            rcdStoreItems("UnitPrice") = txtUnitPrice.Text

            DsFunDS1.Tables("StoreItems").Rows.Add(rcdStoreItems)
            TaStoreItems.Update(DsFunDS1)

            REM Let the user know
            MsgBox("The item has been created")

            btnReset_Click(sender, e)
        Catch ioore As IndexOutOfRangeException
            MsgBox("There is no store item with that number")
        End Try
End Sub

In the Class Name combo box, select btnClose
In the Method Name combo box, select Click

Implement the event as follows:

Private Sub btnClose_Click(ByVal sender As Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnClose.Click
    Close()
End Sub

Display to the Central form
Double-click the Create a New Store Item

Implement the event as follows:

Private Sub btnCreateStoreItem_Click(ByVal sender As System.Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles btnCreateStoreItem.Click
    Dim csi As CreateStoreItem = New CreateStoreItem()
    csi.ShowDialog()
End Sub

In the Class Name combo box, select btnClose
In the Method Name combo box, select Click

Implement the event as follows:

Private Sub btnClose_Click(ByVal sender As Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnClose.Click
        Close()
End Sub

Press Ctrl + F5 to execute the application
Click the Create a New Store Item button

Enter information for a new store item as follows:

Item #:	779208
Manufacturer:	Adrianna Papell
Category:	Women
Sub-Category:	Dresses
Item Name:	Taffeta Ruffled Dress & Bolero Jacket
Size:	4
Unit Price:	288.00
Sale Status	Processing

Click Create

Enter information for a new item as follows:

Item #:	794754
Manufacturer	Calvin Klein
Category	Men
Sub-Category	Pants
Item Name	Black Striped Flat-Front Pants
Size	34W - 30L
Unit Price	99.95
Sale Status	Processing

Click Create
Close the forms and return to your programming environment

Practical Learning: Locating a Record

If necessary, display the Create Store Item form and double-click the Reset button

Change its code as follows:

Private Sub btnReset_Click(ByVal sender As System.Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnReset.Click
        Dim i As Integer
        REM We will use this variable to create a new item number
        Dim newRecordNumber As Integer = 1

        '  Check each record
        For i = 0 To TaStoreItems.GetData().Rows.Count
            '  Get the current record
            Dim rcdCurrentStoreItem As DataRow = TaStoreItems.GetData().Rows(i)
            '  Get the next record
            Dim rcdNextStoreItem As DataRow = TaStoreItems.GetData().Rows(i + 1)

            '  If the item number + 1 of the current record is different from the next
            If ((CInt(CStr(rcdCurrentStoreItem("ItemNumber"))) + 1) <> _
                 CInt(CStr(rcdNextStoreItem("ItemNumber")))) Then
                '  Then use the current item number + 1 as the new item number
                newRecordNumber = CInt(rcdCurrentStoreItem("ItemNumber")) + 1
                Exit For
            End If
        Next

        txtItemNumber.Text = newRecordNumber

        txtManufacturer.Text = ""
        cbxCategories.Text = "Women"
        txtItemName.Text = ""
        txtSize.Text = ""
        txtUnitPrice.Text = "0.00"
        txtManufacturer.Focus()
End Sub

Save all

Practical Learning: Deleting a Record

Display the Manage Store Item form
Double-click the Delete this Item button

Implement its event as follows:

Private Sub btnDeleteStoreItem_Click(ByVal sender As System.Object, _
                                         ByVal e As System.EventArgs) _
                                         Handles btnDeleteStoreItem.Click
        If txtItemNumber.Text.Length = 0 Then
            MsgBox("There is no item to delete." & vbCrLf & _
                   "You must provide an item number")
            Exit Sub
        End If

        '  Just in case the user had just entered an item number
        '  but didn't click the Find button, try to locate that item now
        btnFind_Click(sender, e)

        '  Check with the user to confirm that the item must be deleted
        If MsgBox("Are you sure you want to delete this item?", _
                  MsgBoxStyle.YesNo Or MsgBoxStyle.Question, _
                  "Fun DS - Department Store - Deleting an Item") _
                  = MsgBoxResult.Yes Then
            '  If the user answers Yes, first identify the item
            Dim rcdStoreItem As DataRow = _
                TaStoreItems.GetData().Rows.Find(txtItemNumber.Text)

            rcdStoreItem("Manufacturer") = txtManufacturer.Text
            rcdStoreItem("Category") = cbxCategories.Text
            rcdStoreItem("SubCategory") = cbxSubCategories.Text
            rcdStoreItem("ItemName") = txtItemName.Text
            rcdStoreItem("ItemSize") = txtItemSize.Text
            rcdStoreItem("UnitPrice") = CStr(txtUnitPrice.Text)
            '  Delete the record
            rcdStoreItem.Delete()
            '  Update the table adapter
            TaStoreItems.Update(rcdStoreItem)

            '  Reset the form
            btnReset_Click(sender, e)

            '  Let the user know
            MsgBox("The item has been deleted")
        End If
End Sub

In the Class Name combo box, select btnClose
In the Method Name combo box, select Click

Implement the event as follows:

Private Sub btnClose_Click(ByVal sender As Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnClose.Click
        Close()
End Sub

Press Ctrl + F5 to execute the application
Click the Manage a Store Item button
Enter an item number as 790279 and click Find
If the item is found, click Delete
Click Yes
Close the forms and return to your programming environment

Practical Learning: Introducing Data Analysis

Display the Store Inventory form and change its design as follows:

Control	Text	Name	Other Properties
Label	Select a Column
ComboBox		cbxColumns
Label	Show records that
ComboBox	cbxOperators
TextBox		txtCriterion
Button	Find Record(s)	btnFindRecords
Button	Show Whole Store Items Inventory	Exists already
Button	Close	btnClose

Right-click the form and click View Code
Import the the System.Collections.Generic

Declare two global generic List variables as follows:

Imports System.Collections.Generic

Public Class CurrentStoreInventory
    Private NumericOperators As List(Of String)
    Private StringOperators As List(Of String)

In the Class Name combo box, select btnShowCurrentInventory

Change the code as follows:

Private Sub btnShowCurrentInventory_Click(ByVal sender As System.Object, _
                                              ByVal e As System.EventArgs) _
                                              Handles btnShowCurrentInventory.Click
    Dim i As Integer

    For i = 0 To TaStoreItems.GetData().Rows.Count - 1
            Dim RcdStoreItem As DataRow = TaStoreItems.GetData().Rows(i)

            Dim LviStoreItem As ListViewItem = New ListViewItem(CStr((i + 1)))

            LviStoreItem.SubItems.Add(CStr(RcdStoreItem("ItemNumber")))

            If IsDBNull(RcdStoreItem("Manufacturer")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("Manufacturer")))
            End If

            If IsDBNull(RcdStoreItem("Category")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("Category")))
            End If

            If IsDBNull(RcdStoreItem("SubCategory")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("SubCategory")))
            End If

            If IsDBNull(RcdStoreItem("ItemName")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("ItemName")))
            End If

            If IsDBNull(RcdStoreItem("ItemSize")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("ItemSize")))
            End If

            If IsDBNull(RcdStoreItem("UnitPrice")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CDbl(FormatNumber(RcdStoreItem("UnitPrice"))))
            End If

            If IsDBNull(RcdStoreItem("SaleStatus")) Then
                LviStoreItem.SubItems.Add("")
            Else
                LviStoreItem.SubItems.Add(CStr(RcdStoreItem("SaleStatus")))
            End If

            lvwStoreItems.Items.Add(LviStoreItem)
    Next

    For Each col As DataColumn In TaStoreItems.GetData().Columns
            cbxColumns.Items.Add(col.ColumnName)

            NumericOperators = New List(Of String)
            NumericOperators.Add("Equal To")
            NumericOperators.Add("Is Not Equal To")
            NumericOperators.Add("Less Than")
            NumericOperators.Add("Less Than Or Equal To")
            NumericOperators.Add("Greater Than")
            NumericOperators.Add("Greater Than Or Equal To")

            StringOperators = New List(Of String)

            StringOperators.Add("Equal To")
            StringOperators.Add("Different From")
            StringOperators.Add("Starts With")
            StringOperators.Add("Doesn't Start With")
            StringOperators.Add("Contains")
            StringOperators.Add("Doesn't Contain")
            StringOperators.Add("Ends With")
            StringOperators.Add("Doesn't End With")
    Next
End Sub

In the Class Name combo box, select cbxColumns
In the Method Name combo box, select SelectedIndexChanged

Implement the event as follows:

Private Sub cbxColumns_SelectedIndexChanged(ByVal sender As Object, _
                                                ByVal e As System.EventArgs) _
                                                Handles cbxColumns.SelectedIndexChanged
        For Each col As DataColumn In TaStoreItems.GetData().Columns
            If col.ColumnName.Equals(cbxColumns.Text) Then
                cbxOperators.Items.Clear()

                If col.DataType.Equals(Type.GetType("System.Int32")) Then
                    For Each strOperator As String In NumericOperators
                        cbxOperators.Items.Add(strOperator)
                    Next

                    cbxOperators.SelectedIndex = 0
                ElseIf col.DataType.Equals(Type.GetType("System.Decimal")) Then
                    For Each strOperator As String In NumericOperators
                        cbxOperators.Items.Add(strOperator)
                    Next

                    cbxOperators.SelectedIndex = 0
                ElseIf col.DataType.Equals(Type.GetType("System.String")) Then
                    For Each strOperator As String In StringOperators
                        cbxOperators.Items.Add(strOperator)
                    Next

                    cbxOperators.SelectedIndex = 0
                Else
                    cbxOperators.Items.Clear()
                    cbxOperators.Text = ""
                End If
            End If
        Next
End Sub

Save all

Practical Learning: Analyzing Data With Strings

In the Class Name combo box, select btnFindRecords
In the Method Name combo box, select Click

Implement the event as follows:

Private Sub ShowRecords(ByVal RowStoreItem As DataRow, ByVal counter As Integer)
        Dim LviStoreItem As ListViewItem = New ListViewItem(counter)
        LviStoreItem.SubItems.Add(CStr(RowStoreItem("ItemNumber")))

        If IsDBNull(RowStoreItem("Manufacturer")) Then
            LviStoreItem.SubItems.Add("")
        Else
            LviStoreItem.SubItems.Add(CStr(RowStoreItem("Manufacturer")))
        End If

        If IsDBNull(RowStoreItem("Category")) Then
            LviStoreItem.SubItems.Add("")
        Else
            LviStoreItem.SubItems.Add(CStr(RowStoreItem("Category")))
        End If

        If IsDBNull(RowStoreItem("SubCategory")) Then
            LviStoreItem.SubItems.Add("")
        Else
            LviStoreItem.SubItems.Add(CStr(RowStoreItem("SubCategory")))
        End If

        If IsDBNull(RowStoreItem("ItemName")) Then
            LviStoreItem.SubItems.Add("")
        Else
            LviStoreItem.SubItems.Add(CStr(RowStoreItem("ItemName")))
        End If

        If IsDBNull(RowStoreItem("ItemSize")) Then
            LviStoreItem.SubItems.Add("")
        Else
            LviStoreItem.SubItems.Add(CStr(RowStoreItem("ItemSize")))
        End If

        If IsDBNull(RowStoreItem("UnitPrice")) Then
            LviStoreItem.SubItems.Add("")
        Else
            LviStoreItem.SubItems.Add(FormatNumber(RowStoreItem("UnitPrice")))
        End If

    If IsDBNull(RowStoreItem("SaleStatus")) Then
        LviStoreItem.SubItems.Add("")
    Else
        LviStoreItem.SubItems.Add(CStr(RowStoreItem("SaleStatus")))
    End If

    LvwStoreItems.Items.Add(LviStoreItem)
End Sub

Private Sub btnFindRecords_Click(ByVal sender As Object, _
                                     ByVal e As System.EventArgs) _
                                     Handles BtnFindRecords.Click
        Dim i As Integer
         
        LvwStoreItems.Items.Clear()

        TaStoreItems.Fill(DsFunDS1.StoreItems)

        i = 1

        ' Check the value from the Operator combo box.
        ' If it is Equal To, you will use the = operator
        If CbxOperators.Text.Equals("Equal To") Then
            '                 Check all records
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                ' If the data type of a column is integer-based
                If Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Int32")) Then
                    ' Get the value in the Criterion text box.
                    ' If the value in the Criterion text box = the value in the corresponding record
                    If CInt(CStr(Record(CbxColumns.Text))) = CInt(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If

                ElseIf Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Decimal")) Then
                    If CDec(CStr(Record(CbxColumns.Text))) = CDec(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                Else ' (record(cbxColumns.Text).GetType() == Type.GetType("System.String"))
                    If Not IsDBNull(Record(CbxColumns.Text)) Then
                        If CStr(Record(CbxColumns.Text)).ToLower().Equals(TxtCriterion.Text.ToLower()) Then
                            ShowRecords(Record, i)
                            i = i + 1
                        End If
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Different From") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If CStr(Record(CbxColumns.Text)).ToLower() <> TxtCriterion.Text.ToLower() Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Starts With") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If CStr(Record(CbxColumns.Text)).ToLower().StartsWith(TxtCriterion.Text.ToLower()) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Doesn't Start With") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If Not CStr(Record(CbxColumns.Text)).ToLower().StartsWith(TxtCriterion.Text.ToLower()) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Contains") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If CStr(Record(CbxColumns.Text)).ToLower().Contains(TxtCriterion.Text.ToLower()) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Doesn't Contain") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If Not CStr(Record(CbxColumns.Text)).ToLower().Contains(TxtCriterion.Text.ToLower()) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Ends With") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If CStr(Record(CbxColumns.Text)).ToLower().EndsWith(TxtCriterion.Text.ToLower()) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Doesn't End With") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If Not CStr(Record(CbxColumns.Text)).ToLower().EndsWith(TxtCriterion.Text.ToLower()) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Doesn't Start With") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Not IsDBNull(Record(CbxColumns.Text)) Then
                    If Not CStr(Record(CbxColumns.Text)).ToLower().StartsWith(TxtCriterion.Text.ToLower()) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Less Than") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Int32")) Then
                    If CInt(Record(CbxColumns.Text)) < CInt(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If

                ElseIf Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Decimal")) Then
                    If CDec(CStr(Record(CbxColumns.Text))) < CDec(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                Else
                    Exit Sub
                End If
            Next
        ElseIf CbxOperators.Text.StartsWith("Less Than or Equal") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Int32")) Then
                    If CInt(CStr(Record(CbxColumns.Text))) <= CInt(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                ElseIf Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Decimal")) Then
                    If CDec(CStr(Record(CbxColumns.Text))) <= CDec(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                Else
                    Exit Sub
                End If
            Next
        ElseIf CbxOperators.Text.Equals("Greater Than") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Int32")) Then
                    If CInt(CStr(Record(CbxColumns.Text))) > CInt(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                ElseIf Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Decimal")) Then
                    If CDec(CStr(Record(CbxColumns.Text))) > CDec(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                Else
                    Exit Sub
                End If
            Next
        ElseIf CbxOperators.Text.StartsWith("Greater Than or Equal") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Int32")) Then
                    If CInt(CStr(Record(CbxColumns.Text))) >= CInt(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                ElseIf Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Decimal")) Then
                    If CDec(CStr(Record(CbxColumns.Text))) >= CDec(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                Else
                    Exit Sub
                End If
            Next
        ElseIf CbxOperators.Text.StartsWith("Is Not Equal") Then
            For Each Record As DataRow In DsFunDS1.StoreItems.Rows
                If Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Int32")) Then
                    If CInt(CStr(Record(CbxColumns.Text))) <> CInt(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                ElseIf Record(CbxColumns.Text).GetType().Equals(Type.GetType("System.Decimal")) Then
                    If CDec(CStr(Record(CbxColumns.Text))) <> CDec(TxtCriterion.Text) Then
                        ShowRecords(Record, i)
                        i = i + 1
                    End If
                Else
                    Exit Sub
                End If
            Next
        Else
            Exit Sub
        End If
End Sub

In the Class Name combo box, select btnClose
In the Method Name combo box, select Click

Implement the event as follows:

Private Sub btnClose_Click(ByVal sender As Object, _
                               ByVal e As System.EventArgs) _
                               Handles btnClose.Click
        Close()
End Sub

Execute the application to test it
Display the Store Inventory form and click the Show Whole Store Items Inventory button

Department Store - All store items

Department Store - Items that do not have a manufacturer

Department Store - Items manufactured by Ralph Lauren

Department Store - Items whose prices are over 280