treeview循环绑定数据源

protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            //非回发时加载树 TreeView1为aspx上的树控件
            readSysTree(TreeView1);
        }
    }

    /// <summary>
    /// 加载树
    /// </summary>
    /// <param name="TV"></param>
    public void readSysTree(TreeView TV)
    {
        string sql = "select * from ProductType";
        DataSet ds = cy_class.ExecuteCommand_DS(sql);
        if (ds != null)
        {


            DataTable dt = ds.Tables[0];
            TV.Nodes.Clear();
            DataView dv = new DataView(dt);
            dv.RowFilter = "Type_Parent='root'";//指定数据集的跟节点标识Type_Parent为表里的父级字段 root为根目录标识
            foreach (DataRowView drv in dv)
            {
                TreeNode node = new TreeNode();
                node.Text = drv["Type_Name"].ToString();
                node.Value = drv["Type_Tag"].ToString();
               // node.ImageUrl = "../images/admin_default/gif-0134.gif";

                TV.Nodes.Add(node);
                AddChildNode(dt, node);
                node.ExpandAll();
            }

        }
    }

    /// <summary>
    /// 递归加载子节点
    /// </summary>
    /// <param name="dt"></param>
    /// <param name="node"></param>
    public void AddChildNode(DataTable dt, TreeNode node)
    {
        DataView dv = new DataView(dt);
        dv.RowFilter = "Type_Parent='" + node.Value + "'";
        foreach (DataRowView drv1 in dv)
        {
            TreeNode ChildNode = new TreeNode();
            ChildNode.Text = drv1["Type_Name"].ToString();
            ChildNode.Value = drv1["Type_Tag"].ToString();
            //if (node.Depth == 0)
            //{
            //    ChildNode.ImageUrl = "../images/admin_default/gif-0057.gif";
            //}
            //else
            //{
            //    ChildNode.ImageUrl = "../images/admin_default/gif-0056.gif";
            //}
            ChildNode.Expanded = true; ;
            node.ChildNodes.Add(ChildNode);
            AddChildNode(dt, ChildNode);
        }

    }