VB:将listview中显示出来的记录拖到treeview中去

Option Explicit
Private Sub Form_Load()
TreeView1.Nodes.Add , , "aa", "aa"
TreeView1.Nodes.Add , , "bb", "bb"
ListView1.ListItems.Add , , "cc"
ListView1.ListItems.Add , , "dd"
ListView1.OLEDragMode = ccOLEDragAutomatic
ListView1.LabelEdit = lvwManual
End Sub
Private Sub ListView1_MouseMove(Button As Integer, Shift As Integer, x As Single, y As Single)
If Button = vbLeftButton Then
 ListView1.DragIcon = ListView1.SelectedItem.CreateDragImage
 ListView1.Drag vbBeginDrag
End If
End Sub
Private Sub TreeView1_DragDrop(Source As Control, x As Single, y As Single)
If Not TreeView1.DropHighlight Is Nothing Then
 TreeView1.Nodes.Add TreeView1.DropHighlight.Key, tvwChild, GetNextKey() & ListView1.SelectedItem.Text, ListView1.SelectedItem.Text
 TreeView1.DropHighlight.Expanded = True
End If
End Sub
Private Sub TreeView1_DragOver(Source As Control, x As Single, y As Single, State As Integer)
Set TreeView1.DropHighlight = TreeView1.HitTest(x, y)
End Sub
Private Function GetNextKey() As String
Dim sNewKey As String
Dim iHold As Integer
Dim i As Integer
On Error GoTo myerr
iHold = Val(TreeView1.Nodes(1).Key)
For i = 1 To TreeView1.Nodes.Count
  If Val(TreeView1.Nodes(i).Key) > iHold Then
   iHold = Val(TreeView1.Nodes(i).Key)
  End If
Next
iHold = iHold + 1
sNewKey = CStr(iHold) & "_"
GetNextKey = sNewKey
Exit Function
myerr:
GetNextKey = "1_"
End Function