protected void TreeViewType_SelectedNodeChanged(object sender, EventArgs e)
    {
        TreeView tree = sender as TreeView;
        if (tree != null)
        {
            TreeNode node = tree.SelectedNode;
            if (node != null)
            {
                if (node.Value == "-1")
                    model = 1;
                else if (node.Parent != null && node.Parent.Value == "-1")
                    model = 2;
                else if (node.Parent != null && node.Parent.Value == "-2")
                    model = 3;
                else
                {
                    TreeNode pNode = node;
                    string strValue = null;
                    do
                    {
                        strValue = pNode.Value;
                        pNode = pNode.Parent;
                    }
                    while (pNode.Value != "-1");

                    int.TryParse(strValue, out year);
                    model = 4;
                }
            }
            this.MyGridView1.OnBind();
        }
    }

------解决方案--------------------

冒似WPF中的TREEVIEW节点没有VALUE吧

楼主问的与我这里:
http://topic.csdn.net/u/20081023/15/9a1bf5c6-9e19-4642-ae56-930bdc05466c.html
的大同小异
解决了互相给个通知呀^_^