' 1. Klasse erstellen
Private Class ListBoxItem
Public text As String
Public owner As ListBox
Public Overrides Function ToString() As String
Return text
End Function
Public Sub New(ByVal name As String, ByVal owner As ListBox)
Me.text = name
Me.owner = owner
End Sub
End Class
 
' 2. Eigenschaften setzen
lstBox1.AllowDrop = True
lstBox2.AllowDrop = True
 
' 3. Ereignisse schreiben
Private Sub ListBox_MouseDown(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.MouseEventArgs) Handles lstBox1.MouseDown, _
  lstBox2.MouseDown
Dim box As ListBox = DirectCast(sender, ListBox)
box.DoDragDrop(box.Items(box.SelectedIndex), DragDropEffects.Move)
End Sub
 
Private Sub ListBox_DragEnter(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.DragEventArgs) Handles lstBox1.DragEnter, _
  lstBox2.DragEnter
If e.Data.GetDataPresent(GetType(ListBoxItem)) Then
e.Effect = DragDropEffects.Move
End If
End Sub
 
Private Sub ListBox_DragDrop(ByVal sender As Object, ByVal e As _
  System.Windows.Forms.DragEventArgs) Handles lstBox2.DragDrop, lstBox1.DragDrop
Dim box As ListBox = DirectCast(sender, ListBox)
Dim item As ListBoxItem
If e.Data.GetDataPresent(GetType(ListBoxItem)) Then
item = DirectCast(e.Data.GetData(GetType(ListBoxItem)), ListBoxItem)
If Not item.owner Is sender Then
box.Items.Add(item)
If box Is lstBox1 Then
lstBox2.Items.Remove(item)
Else
lstBox1.Items.Remove(item)
End If
item.owner = box
End If
End If
End Sub

MfG
Visual Studio .Net Team Suite 2008 - Meine neue lieblings IDE