C#创建XML

//更新时写入XML
        protected void GridView2_RowUpdated(object sender, GridViewUpdatedEventArgs e)
        {
            XmlDocument xmldoc = new XmlDocument();
            XmlDeclaration xmldecl = xmldoc.CreateXmlDeclaration("1.0", "GBK", null);   //创建段落申明
            xmldoc.AppendChild(xmldecl);

            XmlElement  root= xmldoc.CreateElement("sysconfig");
            string CmdStr="select * from sysconfig";
            OleDbDataReader Reader=AccessHelper.ExecuteReader(AccessHelper.ConnectionString, CmdStr, null);
            while (Reader.Read()) {
                XmlElement Element = xmldoc.CreateElement("Item");   //创建第一层

                XmlElement c1 = xmldoc.CreateElement("ID");
                XmlElement c2 = xmldoc.CreateElement("参数");
                XmlElement c3 = xmldoc.CreateElement("值");

                c1.InnerText = Reader["ID"].ToString();
                c2.InnerText = Reader["参数"].ToString();
                c3.InnerText = Reader["值"].ToString();

                Element.AppendChild(c1);
                Element.AppendChild(c2);
                Element.AppendChild(c3);

                root.AppendChild(Element);
            }
            xmldoc.AppendChild(root);
        }