Private Sub KSystem_Load(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles MyBase.Load
        dbdata.Connection = dbcon
        dbdata2.Connection = dbcon2
 
        Dim reader As OleDb.OleDbDataReader
        Dim reader2 As OleDb.OleDbDataReader
        Dim maname As String
        Dim tn As TreeNode
 
        dbdata.CommandText = "SELECT * FROM Mitarbeiter WHERE Knoten='- ich" & _
          "selber -'"
        reader = dbdata.ExecuteReader
 
        If reader.HasRows = True Then
            While reader.Read
                Application.DoEvents()
                maname = reader.Item("Name")
 
                tn = TreeView1.Nodes.Add(maname)
 
                dbdata2.CommandText = "SELECT * FROM Mitarbeiter WHERE" & _
                  "Knoten='" & maname & "'"
                reader2 = dbdata2.ExecuteReader
 
                If reader2.HasRows = True Then tn.Nodes.Add("+" & maname)
                reader2.Close()
            End While
        End If
        reader.Close()
    End Sub
    Private Sub TreeView1_BeforeExpand(ByVal sender As Object, ByVal e As _
      System.Windows.Forms.TreeViewCancelEventArgs) Handles _
      TreeView1.BeforeExpand
        Dim tn As TreeNode
        Dim name As String
 
        tn = e.Node
        name = e.Node.Text
        ReadSubmenü(tn, name)
    End Sub
    Private Sub ReadSubmenü(ByVal Knoten As TreeNode, ByVal name As String)
        TreeView1.BeginUpdate()
 
        Knoten.Nodes.Clear()
 
        Dim reader As OleDb.OleDbDataReader
        Dim reader2 As OleDb.OleDbDataReader
        Dim maname As String
        Dim tn As TreeNode
 
        dbdata.CommandText = "SELECT * FROM Mitarbeiter WHERE Knoten='" & name _
          & "'"
        reader = dbdata.ExecuteReader
 
        If reader.HasRows = True Then
            While reader.Read
                Application.DoEvents()
                maname = reader.Item("Name")
 
                tn = Knoten.Nodes.Add(maname)
 
                dbdata2.CommandText = "SELECT * FROM Mitarbeiter WHERE" & _
                  "Knoten='" & maname & "'"
                reader2 = dbdata2.ExecuteReader
 
                If reader2.HasRows = True Then tn.Nodes.Add("+" & maname)
                reader2.Close()
            End While
        End If
        reader.Close()
        TreeView1.EndUpdate()
    End Sub