标题：目录树的问题

Dim tr As WinForm.TreeView
Dim nd As WinForm.TreeNode
tr = Forms("窗口1").Controls("TreeView1")
nd = Tr.Nodes.Add("Root1","根节点一")
nd.Nodes.Add("Sub1","子节点一")
nd.Nodes.Add("Sub2","子节点二")
nd = Tr.Nodes.Add("Root2","根节点二")
nd.Nodes.Add("Sub3","子节点三")
nd.Nodes.Add("Sub4","子节点四")

 这段代码只有提供根节点和子节点的生成方式,但是如果子节点再加上字节点呢?

子节点的子节点，不也有nodes属性吗？

Dim tr As WinForm.TreeView
Dim nd As WinForm.TreeNode
tr = Forms("窗口1").Controls("TreeView1")
nd = Tr.Nodes.Add("Root1","根节点")
nd = nd.Nodes.Add("Sub1","子节点")
nd = nd.Nodes.Add("Sub2","孙节点")

我做来做去:

Dim tr As WinForm.TreeView
Dim nd As WinForm.TreeNode
tr = Forms("窗口1").Controls("TreeView1")
nd = Tr.Nodes.Add("Root1","根节点")
nd = nd.Nodes.Add("Sub1","子节点")
nd = nd.Nodes.Add("Sub2","孙节点")

 红字部分没有加上  nd =    所以一直不对.