控件之间拖放操作-----实现Treeview到Treeview

要求：新建一From窗体，放两个TreeView控件，TreeView1,TreeView2

1>实始化树节点.

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Try
Dim mNode As TreeNode = Me.TreeView1.Nodes.Add("Fruits")
mNode.Nodes.Add("Apple")
mNode.Nodes.Add("Peach")
mNode.Expand()
mNode = Me.TreeView2.Nodes.Add("Vegetables")
mNode.Nodes.Add("Tomato")
mNode.Nodes.Add("Eggplant")
mNode.Expand()
Me.TreeView1.AllowDrop = True
Me.TreeView2.AllowDrop = True

Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub

2>Treeview1的MouseDown事件

Private Sub TreeView1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles TreeView1.MouseDown
Try
Dim mTree As TreeView = sender
Dim mNode As TreeNode = mTree.GetNodeAt(e.X, e.Y)
mTree.SelectedNode = mNode
If Not mNode Is Nothing Then
mTree.DoDragDrop(mNode.Clone, DragDropEffects.Copy)
End If
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub

3>TreeView2的DragOver事件

Private Sub TreeView2_DragOver(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles TreeView2.DragOver
Try
Dim Tree As TreeView = sender
e.Effect = DragDropEffects.None

If Not CType(e.Data.GetData(GetType(TreeNode)), TreeNode) Is Nothing Then
Dim pt As Point = New Point(e.X, e.Y)
pt = Tree.PointToClient(pt)

Dim mNode As TreeNode = Tree.GetNodeAt(pt)
If Not mNode Is Nothing Then
e.Effect = DragDropEffects.Copy
Tree.SelectedNode = mNode
End If
End If

Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub

4>TreeView2的DragDrop事件

Private Sub TreeView2_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles TreeView2.DragDrop
Try
Dim Tree As TreeView = sender
Dim pt As Point = New Point(e.X, e.Y)
pt = Tree.PointToClient(pt)
Dim mNode As TreeNode = Tree.GetNodeAt(pt)
mNode.Nodes.Add(CType(e.Data.GetData(GetType(TreeNode)), TreeNode))
mNode.Expand()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub

5>F5执行．拖放的效果就出来了．