ASP.NET2.0 TreeView控件使用数据库生成目录

     void  creatertree(TreeNode node)
     {
        if (ds_area.Tables.Count > 0)
        {
            foreach (DataRow dr in ds_area.Tables["trade_areacode"].Rows)
            {
                if (dr["Parentcode"].ToString() == node.Value.ToString())
                {
                    //主节点 

                    TreeNode tn = new TreeNode();
                    tn.Text = dr["areaname"].ToString();

                    tn.Value = dr["areacode"].ToString();
                    tn.ShowCheckBox = true;
                    tn.Checked = true;
                    node.ChildNodes.Add(tn);
                    creatertree(tn);
                }
            }
        }
    }

     protected   void  TreeView3_TreeNodePopulate( object  sender, TreeNodeEventArgs e)
     {
        creatertree(e.Node);
    }