treeview点击其节点后，报错。谁能帮我看看啊？解决后立刻结贴


if (u == null) u = new User(Session["userid"].ToString());
            Model.DepartMent dm = new DepartMent(Session["memberid"].ToString());
            DataTable dt = new DataTable();
            int year = int.Parse(Session["Year"].ToString());
            int month = int.Parse(Session["Month"].ToString());
            //根节点
            tvDep.Nodes[0].Text = dm.Name;
            tvDep.Nodes[0].Target = "right";
            tvDep.Nodes[0].NavigateUrl = "QuerryDepData.aspx?DepID=" + dm.ID + "&DepName=" + dm.Name + "&IsEN=0";
            tvDep.Nodes[0].ToolTip = "查看" + dm.Name + "的数据汇总";
            tvDep.Nodes[0].Expanded = true;
            //下属单位的上报状态集合
            dt = StateOperator.GetStatesInDepart(Session["memberid"].ToString(), year * 13 + month, year * 13 + month);            #region 单位节点
            if (dt.Select("LayerID<>'EN'").Length == 0 && tvDep.Nodes[0].ChildNodes.Count>1)
            {
                //没有单位
                tvDep.Nodes[0].ChildNodes.RemoveAt(0);
            }
            else
            {
                //单位根节点
                TreeNode tnDepRoot = tvDep.Nodes[0].ChildNodes[0];
                tnDepRoot.Target = "right";
                tnDepRoot.Expanded = false;
                tnDepRoot.ToolTip = "查看单位的数据汇总";
                tnDepRoot.NavigateUrl = "QuerryDepData.aspx?DepID=AllDep&DepName=所有下级行政单位&IsEN=0";
                //单位子节点
                tnDepRoot.ChildNodes.Clear();
                foreach (DataRow dr in dt.Select("LayerID<>'EN'"))
                {
                    string st = dr["state"].ToString();
                    if (string.IsNullOrEmpty(st)) continue;
                    if (st == "填报")
                    {
                        TreeNode tndep = new TreeNode(dr["Name"].ToString());
                        tndep.ImageUrl = GetImg(st);
                        tndep.SelectAction = TreeNodeSelectAction.None;
                        tnDepRoot.ChildNodes.Add(tndep);
                    }
                    else
                    {
                        tnDepRoot.ChildNodes.Add(MakeNodes(dr["Name"].ToString(), dr["ID"].ToString(), GetImg(st), "CheckDepData.aspx?DepID=" + dr["ID"].ToString() + "&State=" + st + "&DepName=" + dr["name"].ToString() + "&IsEN=0"));
                    }
                }
上面是我绑定的方法文档我点击根节点时候报错：错误: 'tdList' 未定义。。 怎么回事啊？