asp.net ext treepanel 动态加载XML的实现方法

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Data.aspx.cs" Inherits="Data" %> 
cs文件如下： 
public partial class Data : System.Web.UI.Page 
{ 
protected void Page_Load(object sender, EventArgs e) 
{ 
StreamReader sr = new StreamReader(Server.MapPath("") + "\\xml-tree-data.xml"); 
Response.ContentType = "text/xml; charset=iso-8859-1"; 
string _temp = sr.ReadToEnd(); 
sr.Close(); 
Response.Write(_temp); 
Response.End(); 
} 
}