asp.net读取xml方法

/// <summary>        /// 读取城市列表        /// </summary>        public void CityList() {            StringBuilder sb = new StringBuilder();            XmlDocument xmldoc = new XmlDocument();            xmldoc.Load(Server.MapPath("/XmlData/City.xml"));//加载xml            XmlNodeList xmlnlist = xmldoc.SelectNodes("/Cities/City");//读取xml的节点列表            for (int i = 0; i < xmlnlist.Count; i++) {                sb.Append("<a href=/"index.aspx?cityid=" + xmlnlist[i].Attributes["ID"] .Value+ "/">" + xmlnlist[i].Attributes["CityName"] .Value+ "</a>");//循环读取里面的值            }            citys = sb.ToString();        }////------附xml格式------/////////////////<?xml version="1.0" encoding="utf-8"?><Cities>  <City ID="218" CityName="南宁" PID="20" ZipCode="530000">南宁</City>  <City ID="219" CityName="柳州" PID="20" ZipCode="545000">柳州</City>  <City ID="228" CityName="贺州" PID="20" ZipCode="542800">贺州</City></Cities>