XML文件操作

XmlDocument doc = new XmlDocument();
            string strtxt = "";
            doc.Load(Server.MapPath("XMLFile1.xml"));
            XmlNode root = doc.DocumentElement;
            foreach (XmlNode personElement in root.ChildNodes)
            {
                strtxt += "ID=" + personElement.Attributes["id"].Value + "value=" + personElement.Attributes["value"].Value + "</br>";
                foreach (XmlNode xmlchild in personElement.ChildNodes)
                {
                    strtxt += "&nbsp;&nbsp;&nbsp;二级：ID=" + xmlchild.Attributes["id"].Value + "value=" + xmlchild.Attributes["value"].Value + "</br>";
                    foreach (XmlNode xmlchild2 in xmlchild.ChildNodes)
                    {
                        strtxt += "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;三级：ID=" + xmlchild2.Attributes["id"].Value + "value=" + xmlchild2.Attributes["value"].Value + "</br>";
                    }
   &n