轻松实现控件间托拽操作

在Vb.net里实现ListBox之间的托拽，首先要使接受托拽数据的控件的AllowDrop属性设为真。再要处理的就是托拽效果，AllowedEffect是设置托拽的源控件的动作效果，而Effect是设置目标控件的动作。这些东东可以在DragEventArgs Members中查到！

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim i As Int32

For i = 0 To 9

ListBox1.Items.Add("Item " & i)

Next

ListBox2.AllowDrop = True

End Sub

Private Sub ListBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles ListBox1.MouseDown

Dim itemIndex As Integer

itemIndex = ListBox1.IndexFromPoint(e.X, e.Y)

If itemIndex >= 0 Then

ListBox1.DoDragDrop(ListBox1.Items(itemIndex), DragDropEffects.Copy)

End If

End Sub

Private Sub ListBox2_DragEnter(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles ListBox2.DragEnter

If (e.Data.GetDataPresent(DataFormats.Text)) Then

e.Effect = DragDropEffects.Copy

Else

e.Effect = DragDropEffects.None

End If

End Sub

Private Sub ListBox2_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles ListBox2.DragDrop

Dim sItem As String

sItem = e.Data.GetData(DataFormats.Text).ToString

ListBox2.Items.Add(sItem)

ListBox1.Items.RemoveAt(ListBox1.FindString(sItem))

End Sub