如何將自定義對象添加到VB 2010的列表框中

Question

我正在開發一個vb應用程序。在那裏我有一個列表框。我想添加不同類型的項目。像不同的彩色和不同對齊的文本（如一個項目項目右對齊，另一個左對齊）。你能告訴我，我怎麼能這樣做。

謝謝。

Answer 1

這是我如何做它在我的項目之一（原代碼是在C＃）：

Public Class ColoringStepCommandListBox 
    Inherits CommandListBox 

    Const ItemHeight As Integer = 20 

    Public Sub New() 
     listBox.ItemHeight = ItemHeight 
     listBox.DrawMode = DrawMode.OwnerDrawFixed 
    End Sub 

    Protected Overrides Sub OnDrawItem(sender As Object, e As DrawItemEventArgs) 
     Const textFormatFlags__1 As TextFormatFlags = TextFormatFlags.EndEllipsis Or TextFormatFlags.PreserveGraphicsClipping Or TextFormatFlags.VerticalCenter 
     Const colorRectangleWidth As Integer = 100, textLeft As Integer = 110 

     If e.Index >= 0 Then 
      'Cast the listbox item to your custom type (ColoringStep in my example). 
      Dim coloringStep = TryCast(listBox.Items(e.Index), ColoringStep) 

      e.DrawBackground() 

      'Do custom coloring and rendering, draw icons etc. 
      Dim colorRect = New Rectangle(2, e.Bounds.Top + 2, colorRectangleWidth, ItemHeight - 5) 
      Dim innerRect = New Rectangle(colorRect.Left + 1, colorRect.Top + 1, colorRect.Width - 1, colorRect.Height - 1) 
      e.Graphics.DrawRectangle(Pens.Black, colorRect) 
      DrawingHelper.DrawGradient(coloringStep, e.Graphics, innerRect, LinearGradientMode.Horizontal) 

      'Draw the text (this does not happen automatically any more with owner draw modes). 
      Dim textRect = New Rectangle(textLeft, e.Bounds.Top, e.Bounds.Width - textLeft, e.Bounds.Height) 
      TextRenderer.DrawText(e.Graphics, coloringStep.ToString(), e.Font, textRect, e.ForeColor, textFormatFlags__1) 

      e.DrawFocusRectangle() 
     End If 
    End Sub 
End Class 

Answer 2

我得到這個簡單的解決方案。下面是代碼

Private Sub ListBox1_DrawItem(ByVal sender As Object, ByVal e As System.Windows.Forms.DrawItemEventArgs) Handles ListBox1.DrawItem 
    e.DrawBackground() 
    Dim textFont As New Font(e.Font.FontFamily, e.Font.Size * 4) 
    e.Graphics.DrawString(ListBox1.Items(e.Index).ToString(), textFont, New SolidBrush(Color.BlueViolet), RectangleF.op_Implicit(e.Bounds)) 
    e.DrawFocusRectangle() 
End Sub 

Private Sub listBox1_MeasureItem(ByVal sender As Object, ByVal e As System.Windows.Forms.MeasureItemEventArgs) Handles ListBox1.MeasureItem 
    e.ItemHeight = e.ItemHeight * 4 
End Sub 

您可以添加ListBox1_DrawItem方法中額外的代碼定製項目