主题：[求助]加TreeView的事件出错

怎么动态添加 TreeView 的 事件，下面的代码出错
Dim frm As WinForm.Form = Forms("TreeTest")
frm.Open()
Dim trv As WinForm.TreeView
Dim nd As WinForm.TreeNode
trv = frm.CreateControl("Trv1", ControlTypeEnum.TreeView)
trv.Dock = 5
nd = trv.Nodes.Add("Root1","根节点一")
nd.Nodes.Add("Sub1","子节点一")
nd.Nodes.Add("Sub2","子节点二")
nd = trv.Nodes.Add("Root2","根节点二")
nd.Nodes.Add("Sub3","子节点三")
nd.Nodes.Add("Sub4","子节点四")
frm.AddControl(trv)
AddHandler trv.AfterSelectNode, AddressOf TreeView_AfterSelectNode
请大大们帮忙解决