'Treeview-Knoten gemäß Datarelations erstellen
        Dim nd_i, nd_k As TreeNode
        Dim row_i, row_k As DataRow  'aktuelle Datarow in Schleife
        Dim rel_i, rel_k As String   'Name der Datarelation
        Dim col_i, col_k As Integer  'Index der anzuzeigenden Spalte im Treeview
        Dim val_i, val_k As String   'anzuzeigender Daten-Wert im Treeview
 
        dtx = ds.Tables(2).Clone
        dgv.DataSource = dtx