Private Function Treeview_CloneNodes(ByVal trv As TreeView) As TreeView
 
    Dim trvc As New TreeView
 
    For i As Integer = 0 To trv.Nodes.Count - 1
        Dim tnc As TreeNode = CType(trv.Nodes(i).Clone, TreeNode)
        trvc.Nodes.Add(tnc)
    Next i
 
    Return trvc
End Function
 
'oder bei bereits vorhandenem 2. Treeview
Private Sub Treeview_CloneNodes(ByVal trv As TreeView, trv2 As TreeView)
 
    trv2.Nodes.Clear()
 
    For i As Integer = 0 To trv.Nodes.Count - 1
       Dim tnc As TreeNode = CType(trv.Nodes(i).Clone, TreeNode)
       trv2.Nodes.Add(tnc)
    Next i
 
 End Sub