asp.net中TreeView的大数据加载速度优化

   <asp:Panel ID="Panel2" runat="server" Height="600px" ScrollBars="Auto">
                        <asp:TreeView ID="TreeView1" runat="server" ForeColor="Black" OnTreeNodeExpanded="TreeView1_TreeNodeExpanded" OnSelectedNodeChanged="TreeView1_SelectedNodeChanged">
                            <LeafNodeStyle HorizontalPadding="3px" />
                            <ParentNodeStyle HorizontalPadding="3px" />
                            <RootNodeStyle HorizontalPadding="3px" />
                            <SelectedNodeStyle ForeColor="#009933" />
                        </asp:TreeView>
                    </asp:Panel>

  #region wsw更改树的加载方式
    private void LoadNewTree()
    {
        DataTable dtp = pagBLL.GetList(" superfuncid=0  order by sort asc").Tables[0];
        if (dtp.Rows.Count > 0)
        {
            //首先清除树型控件内的结点
            this.TreeView1.Nodes.Clear();
            for (int i = 0; i < dtp.Rows.Count; i++)
            {

                //实例出一个结点
                TreeNode Node = new TreeNode();
                Node.Text = dtp.Rows[i]["funcname"].ToString();
                Node.Value = dtp.Rows[i]["pagefuncid"].ToString();
                Node.ToolTip = dtp.Rows[i]["funcurl"].ToString();
                Node.ImageUrl = "../../" + dtp.Rows[i]["imageurl"].ToString(); 
                this.TreeView1.Nodes.Add(Node);//增加父节点，这时直接往树TreeView1上加
                this.LoadAddSign(Node.ChildNodes,Convert.ToInt32(dtp.Rows[i]["pagefuncid"].ToString()));//wsw更改
                TreeView1.CollapseAll();

            }
        }
    }
    /// <summary>
    /// 用于加载显示 树形控件 +号的,加载下面的一个节点。
    /// </summary>
    /// <param name="Conn"></param>
    /// <param name="tn"></param>
    /// <param name="DeptId"></param>
    private void LoadAddSign( TreeNodeCollection tn, int DeptId) //wsw更改
    {
        DataTable table = pagBLL.GetList(" superfuncid=" + DeptId + "  order by sort asc").Tables[0];
        if (table.Rows.Count > 0)
        {
            //加载"一个"1级节点，就是为了显示 + 号
            tn.Add(new TreeNode());

        }
    }
    /// <summary>
    /// 点击 + 号是节点展开事件
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void TreeView1_TreeNodeExpanded(object sender, TreeNodeEventArgs e)
    {
        TreeNode node = e.Node;
        if (node.Expanded == true)
        {
            string bm = e.Node.Value.ToString();//wsw更改
            DataTable table = pagBLL.GetList(" superfuncid=" + bm + "  order by sort asc").Tables[0];

            node.ChildNodes.Clear(); //清除之前加载的空节点。
            if (table.Rows.Count > 0)
            {
                for (int i = 0; i < table.Rows.Count; i++)
                {
                    TreeNode Node = new TreeNode();
                    Node.Text = table.Rows[i]["funcname"].ToString();
                    Node.Value = table.Rows[i]["pagefuncid"].ToString();
                    Node.ToolTip = table.Rows[i]["funcurl"].ToString();
                    Node.ImageUrl = "../../" + table.Rows[i]["imageurl"].ToString();
                    node.ChildNodes.Add(Node);//增加父节点，这时直接往树TreeView1上加
                    this.LoadAddSign(Node.ChildNodes, Convert.ToInt32(table.Rows[i]["pagefuncid"].ToString()));//wsw更改
                }

            }
        }

    }
    #endregion