Public Class TreeViewEx
    Inherits System.Windows.Forms.TreeView
 
    Public Sub AddPath(ByVal Path As String)
        Dim parts() As String = _
             Path.Split(New String() {MyBase.PathSeparator}, _
                    StringSplitOptions.RemoveEmptyEntries)
 
        If Not Me.Nodes.ContainsKey(parts(0)) Then
            Me.Nodes.Add(parts(0), parts(0))
        End If
 
        Dim n As TreeNode = Me.Nodes(parts(0))
        For i As Integer = 1 To parts.Count - 1
            If Not n.Nodes.ContainsKey(parts(i)) Then
                n.Nodes.Add(parts(i), parts(i))
            End If
            n = n.Nodes(parts(i))
        Next i
    End Sub
End Class