VB.NET DrawItemEventArgs.DrawFocusRectangle方法代码示例

Private WithEvents ListBox1 As New ListBox()

Private Sub InitializeListBox() 
    ListBox1.Items.AddRange(New Object() _
        {"Red Item", "Orange Item", "Purple Item"})
    ListBox1.Location = New System.Drawing.Point(81, 69)
    ListBox1.Size = New System.Drawing.Size(120, 95)
    ListBox1.DrawMode = DrawMode.OwnerDrawFixed
    Controls.Add(ListBox1)

End Sub

Private Sub ListBox1_DrawItem(ByVal sender As Object, _
 ByVal e As System.Windows.Forms.DrawItemEventArgs) _
 Handles ListBox1.DrawItem

    ' Draw the background of the ListBox control for each item.
    e.DrawBackground()

    ' Define the default color of the brush as black.
    Dim myBrush As Brush = Brushes.Black

    ' Determine the color of the brush to draw each item based on   
    ' the index of the item to draw.
    Select Case e.Index
        Case 0
            myBrush = Brushes.Red
        Case 1
            myBrush = Brushes.Orange
        Case 2
            myBrush = Brushes.Purple
    End Select

    ' Draw the current item text based on the current 
    ' Font and the custom brush settings.
    e.Graphics.DrawString(ListBox1.Items(e.Index).ToString(), _
        e.Font, myBrush, e.Bounds, StringFormat.GenericDefault)

    ' If the ListBox has focus, draw a focus rectangle around  _ 
    ' the selected item.
    e.DrawFocusRectangle()
End Sub

' 导入命名空间
Imports System
Imports System.Drawing
Imports System.Windows.Forms


Public Class MainClass


   Public Shared Sub Main()
         Application.Run(New OwnerDrawnVariableListBox())
   End Sub
   
   
End Class

Public Class OwnerDrawnVariableListBox
    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()

        'Add any initialization after the InitializeComponent() call

    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

    '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 listBox2 As System.Windows.Forms.ListBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.listBox2 = New System.Windows.Forms.ListBox()
        Me.SuspendLayout()
        '
        'listBox2
        '
        Me.listBox2.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawVariable
        Me.listBox2.Items.AddRange(New Object() {"A", "a", "B"})
        Me.listBox2.Location = New System.Drawing.Point(6, 15)
        Me.listBox2.Name = "listBox2"
        Me.listBox2.Size = New System.Drawing.Size(280, 192)
        Me.listBox2.TabIndex = 5
        '
        'OwnerDrawnVariableListBox
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(292, 222)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.listBox2})
        Me.Name = "OwnerDrawnVariableListBox"
        Me.Text = "OwnerDrawnVariableListBox"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub listBox2_DrawItem(ByVal sender As Object, ByVal e As System.Windows.Forms.DrawItemEventArgs) Handles listBox2.DrawItem
        e.DrawBackground()

        Dim textFont As Font
        textFont = New Font(e.Font.FontFamily, e.Font.Size * 2)

        e.Graphics.DrawString(listBox2.Items(e.Index).ToString(), _
                                textFont, _
                                New SolidBrush(e.ForeColor), _
                                e.Bounds.X, e.Bounds.Y)

        e.DrawFocusRectangle()
    End Sub

    Private Sub listBox2_MeasureItem(ByVal sender As Object, ByVal e As System.Windows.Forms.MeasureItemEventArgs) Handles listBox2.MeasureItem
        If e.Index Mod 2 = 0 Then e.ItemHeight *= 2
    End Sub
End Class