Public Class FrmDatatable2Treeview
 
    Dim dt As New DataTable
    Dim bs As New BindingSource
 
    Dim dgv As New DataGridView With
        {.Parent = Me, .Width = 300, .DataSource = bs}
 
    Dim trv As New TreeView With
        {.Parent = Me, .Left = 310, .Width = 300, .Scrollable = True}
 
 
    Private Sub FrmDatatable2Treeview_Load(sender As Object,
                                 e As EventArgs) Handles MyBase.Load
 
        Me.Size = New Size(630, 300)
 
        'Testdaten
        With dt
            With .Columns
                .Add("Menge", GetType(Integer))
                .Add("Material") : .Add("Händler") : .Add("Qualität")
                .Add("Status")
            End With
 
            With .Rows
                .Add(20, "Holz", "Meyer", "Premium", "lagernd")
                .Add(40, "Kohlen", "Schulz", "Bruch", "bestellt")
                .Add(45, "Kohlen", "schulz", "Bruch", "bestellt")
                .Add(12, "Koks", "Schneider", "Bruch", "lagernd")
                .Add(10, "Holz", "Meyer", "Medium", "lagernd")
                .Add(15, "Kohlen", "Schulz", "Premium", "geliefert")
                .Add(20, "Propan", "Meyer", "Premium", "geliefert")
                .Add(5, "Propan", "Schulz", "Medium", "bestellt")
                .Add(10, "Holz", "Schulz", "Bruch", "lagernd")
                .Add(30, "Kohlen", "Müller", "Medium", "")
                .Add(20, "Kohlen", "Müller", "Bruch", "")
                .Add(200, "Koks", "Müller", "Bruch", "lagernd")
            End With
        End With
 
        bs.DataSource = dt 'Datenbindung
 
        'Sortieren der Datenspalten: Festlegung der Knotenfolge im Treeview 
        bs.Sort = "Händler DESC, Material, Qualität"
 
        'Übertragung von Spaltenwerten ins Treeview (Knoten-Hierarchie): 
        'Händler(2), Material(1), Qualität(3), Menge(0)
        DatatableColumns2Treeview(bs, New Integer() {2, 1, 3, 0}, trv)
 
    End Sub
 
 
    Private Function DatatableColumns2Treeview(ByVal bs As BindingSource, _
                     ByVal columnindices() As Integer, _
                     trv As TreeView) As Boolean
 
        If bs Is Nothing Or trv Is Nothing Then Return False
        If bs.DataSource Is Nothing Then Return False
        If Not TypeOf bs.DataSource Is DataTable Then Return False
 
        'Spaltenindices prüfen
        If columnindices Is Nothing OrElse
           columnindices.Length < 2 Then Return False
 
        For i As Integer = 0 To columnindices.Length - 1
            If columnindices(i) < 0 Or
                columnindices(i) > dt.Columns.Count - 1 Then Return False
        Next i
 
        trv.Nodes.Clear()
 
        Try
            'Zeilen in der Datatable durchlaufen 
            For r As Integer = 0 To bs.Count - 1
                Dim row As DataRow = DirectCast(bs(r), DataRowView).Row
                'Knoten-Pfad aus Spaltenwerten zusammensetzen
                Dim path As String = ""
                For i As Integer = 0 To columnindices.Length - 1
                    path &= row(columnindices(i)).ToString
                    If i < columnindices.Length - 1 Then path &= _
                      trv.PathSeparator
                Next i
 
                GetTreeNodeByPath(trv.Nodes, path)
            Next r
            Return True
        Catch
            Return False
        End Try
    End Function
 
 
    ''' <summary>In der Collection wird ein Pfad-Knoten ermittelt/erstellt</summary>
    ''' <param name="Nodes">Node-Collection</param>
    ''' <param name="path">zu suchender/zu erstellender Pfad</param>
    ''' <returns>Treenode</returns>
    Private Function GetTreeNodeByPath(ByVal Nodes As TreeNodeCollection, _
                                       path As String) As TreeNode
 
        Dim parts() As String =
            path.Split({trv.PathSeparator}, StringSplitOptions.None)
 
        Dim nd As TreeNode, ind As Integer, c As Integer = -1
 
        'Pfad durchlaufen
        Do
            c += 1
            ind = Nodes.IndexOfKey(parts(c))
            If ind = -1 Then
                'Pfad-Knoten fehlt in Auflistung, wird erstellt 
                nd = Nodes.Add(parts(c), parts(c))
            Else
                nd = Nodes(parts(c))
            End If
            Nodes = nd.Nodes
        Loop While c < parts.Length - 1
 
        Return nd
 
    End Function
End Class