堆栈,我不知道怎么写不过用递归可以实现,

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim Node As TreeNode
        Dim str As String
        str = TextBox1.Text
        Node = TreeView1.Nodes.Add(str.Substring(0, 2))
        Loadtree(Mid(str, 3), Node)

    End Sub
    Private Sub Loadtree(ByVal str As String, ByVal Node As TreeNode)
        If str.Length >= 2 Then
            Node = Node.Nodes.Add(str.Substring(0, 2))
            Loadtree(Mid(str, 3), Node)
        End If
    End Sub

谢谢，我先试试。不懂再请教你！