Object-Oriented database design with the DatabaseObjects library

Option Strict Off
Option Explicit On 

Imports NorthwindDatabase

Friend Class frmProducts
    Inherits System.Windows.Forms.Form

#Region "Windows Form Designer generated code "
	Public Sub New()
		MyBase.New()
        'This call is required by the Windows Form Designer.
		InitializeComponent()
	End Sub
	'Form overrides dispose to clean up the component list.
	Protected Overloads Overrides Sub Dispose(ByVal Disposing As Boolean)
		If Disposing Then
			If Not components Is Nothing Then
				components.Dispose()
			End If
		End If
		MyBase.Dispose(Disposing)
	End Sub
	'Required by the Windows Form Designer
	Private components As System.ComponentModel.IContainer
	Public ToolTip1 As System.Windows.Forms.ToolTip
    Public WithEvents cmdClose As System.Windows.Forms.Button
	'NOTE: The following procedure is required by the Windows Form Designer
	'It can be modified using the Windows Form Designer.
	'Do not modify it using the code editor.
    Friend WithEvents tvwCategories As System.Windows.Forms.TreeView
    Friend WithEvents lvwProducts As System.Windows.Forms.ListView
    Friend WithEvents ColumnHeader1 As System.Windows.Forms.ColumnHeader
    Friend WithEvents ColumnHeader2 As System.Windows.Forms.ColumnHeader
    Friend WithEvents ColumnHeader3 As System.Windows.Forms.ColumnHeader
    Friend WithEvents ColumnHeader4 As System.Windows.Forms.ColumnHeader

    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.components = New System.ComponentModel.Container
        Me.ToolTip1 = New System.Windows.Forms.ToolTip(Me.components)
        Me.cmdClose = New System.Windows.Forms.Button
        Me.tvwCategories = New System.Windows.Forms.TreeView
        Me.lvwProducts = New System.Windows.Forms.ListView
        Me.ColumnHeader1 = New System.Windows.Forms.ColumnHeader
        Me.ColumnHeader2 = New System.Windows.Forms.ColumnHeader
        Me.ColumnHeader3 = New System.Windows.Forms.ColumnHeader
        Me.ColumnHeader4 = New System.Windows.Forms.ColumnHeader
        Me.SuspendLayout()
        '
        'cmdClose
        '
        Me.cmdClose.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
        Me.cmdClose.BackColor = System.Drawing.SystemColors.Control
        Me.cmdClose.Cursor = System.Windows.Forms.Cursors.Default
        Me.cmdClose.DialogResult = System.Windows.Forms.DialogResult.Cancel
        Me.cmdClose.Font = New System.Drawing.Font("Arial", 8.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.cmdClose.ForeColor = System.Drawing.SystemColors.ControlText
        Me.cmdClose.Location = New System.Drawing.Point(617, 412)
        Me.cmdClose.Name = "cmdClose"
        Me.cmdClose.RightToLeft = System.Windows.Forms.RightToLeft.No
        Me.cmdClose.Size = New System.Drawing.Size(89, 24)
        Me.cmdClose.TabIndex = 2
        Me.cmdClose.Text = "&Close"
        '
        'tvwCategories
        '
        Me.tvwCategories.Anchor = CType(((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
                    Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)
        Me.tvwCategories.ImageIndex = -1
        Me.tvwCategories.Location = New System.Drawing.Point(4, 4)
        Me.tvwCategories.Name = "tvwCategories"
        Me.tvwCategories.SelectedImageIndex = -1
        Me.tvwCategories.Size = New System.Drawing.Size(220, 400)
        Me.tvwCategories.TabIndex = 0
        '
        'lvwProducts
        '
        Me.lvwProducts.Anchor = CType((((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
                    Or System.Windows.Forms.AnchorStyles.Left) _
                    Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
        Me.lvwProducts.Columns.AddRange(New System.Windows.Forms.ColumnHeader() {Me.ColumnHeader1, Me.ColumnHeader2, Me.ColumnHeader3, Me.ColumnHeader4})
        Me.lvwProducts.Location = New System.Drawing.Point(228, 4)
        Me.lvwProducts.Name = "lvwProducts"
        Me.lvwProducts.Size = New System.Drawing.Size(477, 398)
        Me.lvwProducts.TabIndex = 1
        Me.lvwProducts.View = System.Windows.Forms.View.Details
        '
        'ColumnHeader1
        '
        Me.ColumnHeader1.Text = "Name"
        Me.ColumnHeader1.Width = 120
        '
        'ColumnHeader2
        '
        Me.ColumnHeader2.Text = "Supplier"
        Me.ColumnHeader2.Width = 120
        '
        'ColumnHeader3
        '
        Me.ColumnHeader3.Text = "Unit Price"
        Me.ColumnHeader3.TextAlign = System.Windows.Forms.HorizontalAlignment.Right
        Me.ColumnHeader3.Width = 70
        '
        'ColumnHeader4
        '
        Me.ColumnHeader4.Text = "Quantity Per Unit"
        Me.ColumnHeader4.TextAlign = System.Windows.Forms.HorizontalAlignment.Right
        Me.ColumnHeader4.Width = 100
        '
        'frmProducts
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.BackColor = System.Drawing.SystemColors.Control
        Me.CancelButton = Me.cmdClose
        Me.ClientSize = New System.Drawing.Size(710, 447)
        Me.Controls.Add(Me.lvwProducts)
        Me.Controls.Add(Me.tvwCategories)
        Me.Controls.Add(Me.cmdClose)
        Me.Cursor = System.Windows.Forms.Cursors.Default
        Me.Font = New System.Drawing.Font("Arial", 8.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Location = New System.Drawing.Point(3, 29)
        Me.MinimizeBox = False
        Me.Name = "frmProducts"
        Me.RightToLeft = System.Windows.Forms.RightToLeft.No
        Me.ShowInTaskbar = False
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent
        Me.Text = "Products"
        Me.ResumeLayout(False)

    End Sub
#End Region 

	Private Sub LoadCategories()

        Dim objCategory As Category
        Dim objRoot As TreeNode
		
        With Me.tvwCategories.Nodes
            objRoot = .Add("All")
            For Each objCategory In NorthwindDB.Categories
                objRoot.Nodes.Add(objCategory.Name)
            Next
            objRoot.Expand()
        End With
		
	End Sub
	
    Private Sub LoadProducts(ByVal objProducts As Products)

        Dim objProduct As Product

        With Me.lvwProducts.Items
            .Clear()
            For Each objProduct In objProducts
                With .Add(objProduct.Name)
                    .SubItems.Add(objProduct.Supplier.Name)
                    .SubItems.Add(objProduct.UnitPrice)
                    .SubItems.Add(objProduct.QuantityPerUnit)
                End With
            Next
        End With

    End Sub

    Private Sub frmProducts_Load(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles MyBase.Load

        LoadCategories()
        LoadProducts(NorthwindDB.Products)

    End Sub

    Private Sub cmdClose_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles cmdClose.Click

        Me.Close()

    End Sub

    Private Sub tvwCategories_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles tvwCategories.Click

    End Sub

    Private Sub tvwCategories_AfterSelect(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles tvwCategories.AfterSelect

        If e.Node.Parent Is Nothing Then
            LoadProducts(NorthwindDB.Products)
        Else
            LoadProducts(NorthwindDB.Categories(e.Node.Text).Products)
        End If

    End Sub

End Class