使用XmlDocument中的XmlElement遍历xml文档

xml文件各个层次的节点名称都一样，所以不能使用DataSet.ReadXml来加载，必须使用XmlDocument对象：

<?xml version='1.0' encoding='UTF-8'?>
 <Value>
   <Value nodename="北京市" nodeid="110000">
     <Value nodename="市辖区" nodeid="110100">
       <Value nodename="东城区" nodeid="110101" />
       <Value nodename="怀柔区" nodeid="110116" />
       <Value nodename="平谷区" nodeid="110117" />
    </Value>
     <Value nodename="县" nodeid="110200">
       <Value nodename="密云县" nodeid="110228" />
       <Value nodename="延庆县" nodeid="110229" />
    </Value>
  </Value>
   <Value nodename="天津市" nodeid="120000">
     <Value nodename="市辖区" nodeid="120100">
       <Value nodename="和平区" nodeid="120101" />
       <Value nodename="河东区" nodeid="120102" />
       <Value nodename="河西区" nodeid="120103" />
       <Value nodename="宝坻区" nodeid="120115" />
     </Value>
     <Value nodename="县" nodeid="120200">
       <Value nodename="宁河县" nodeid="120221" />
       <Value nodename="静海县" nodeid="120223" />
       <Value nodename="蓟　县" nodeid="120225" />
    </Value>
  </Value>
   <Value nodename="河北省" nodeid="130000">
     <Value nodename="石家庄市" nodeid="130100">
       <Value nodename="市辖区" nodeid="130101" />
       <Value nodename="新华区" nodeid="130105" />
     </Value>
  </Value>
</Value>

aspx.cs，转换成符合逻辑层次标准的xml文档

        string str = "<?xml version=\"1.0\" encoding=\"utf-8\"?>";

        str += "<item>";

        XmlDocument xmldc = new XmlDocument();
        xmldc.Load(Server.MapPath("XMLFile.xml"));

        XmlElement el = xmldc.DocumentElement;

        for (int i = 0; i < el.ChildNodes.Count; i++)
        {
            XmlNode nodeProvince = el.ChildNodes[i];
            string province = nodeProvince.Attributes["nodename"].Value;
            string provinceID = nodeProvince.Attributes["nodeid"].Value;

            str += "<province name=\"" + province + "\" id=\"" + provinceID + "\">";

            for (int j = 0; j < el.ChildNodes[i].ChildNodes.Count; j++)
            {
                XmlNode nodeCity = el.ChildNodes[i].ChildNodes[j];
                string city = nodeCity.Attributes["nodename"].Value;
                string cityID = nodeCity.Attributes["nodeid"].Value;

                str += "<city name=\"" + city + "\" id=\"" + cityID + "\" provinceID=\"" + provinceID + "\">";

                for (int k = 0; k < el.ChildNodes[i].ChildNodes[j].ChildNodes.Count; k++)
                {
                    XmlNode nodedistrinct = el.ChildNodes[i].ChildNodes[j].ChildNodes[k];
                    string distrinct = nodedistrinct.Attributes["nodename"].Value;
                    string distrinctID = nodedistrinct.Attributes["nodeid"].Value;

                    str += "<distrinct name=\"" + distrinct + "\" distrinctID=\"" + distrinctID + "\" cityID=\"" + cityID + "\" provinceID=\"" + provinceID + "\" />";

                }

                str += "</city>";
            }

            str += "</province>";
        }


        str += "</item>";

        Response.Write(str);