常用的方法，读取XML节点并赋值给List集合

一、前言

很多时候也可以直接在XML文件中配置好节点，在程序需要用到的时候，修改XML文件并不需要重新编译，这里是在极光推送中拿出来的一部分代码。代码简单，大家直接看例子吧。

二、实现过程

1.新创建一个AppKey.xml

<?xml version="1.0" encoding="utf-8" ?>
<root>
  <JPushKeyList>

    <PushKey>
      <AppKey>1111</AppKey>
      <MasterSecret>2222</MasterSecret>
    </PushKey>

    <PushKey>
      <AppKey>333</AppKey>
      <MasterSecret>444</MasterSecret>
    </PushKey>

    <PushKey>
      <AppKey>555</AppKey>
      <MasterSecret>666</MasterSecret>
    </PushKey>

  </JPushKeyList>

  <EngJPushKeyList>

  </EngJPushKeyList>

</root>

2.获取PushKey的List集合方法

    private static List<PushServer.JPushKey> PushKeyListGet()
        {
            List<PushServer.JPushKey> jPushKeyList = new List<PushServer.JPushKey>();
            //string xmlFilePath = HttpRuntime.AppDomainAppPath + "AppKey.xml";
            string xmlFilePath = System.IO.Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, "AppKey.xml");

            XmlNodeList nodeList;
            nodeList = Utility.XMLHelper.GetXmlNodeListByXpath(xmlFilePath, "/root/JPushKeyList/PushKey");
            foreach (XmlNode n in nodeList)
            {
                string strAppKey = n.SelectSingleNode("AppKey").InnerXml;
                string strMasterSecret = n.SelectSingleNode("MasterSecret").InnerXml;
                PushServer.JPushKey key = new PushServer.JPushKey(strAppKey, strMasterSecret);
                jPushKeyList.Add(key);
            }

            return jPushKeyList;

        }

3.  选择匹配XPath表达式的节点列表XmlNodeList

    /// <summary>
        /// 选择匹配XPath表达式的节点列表XmlNodeList.
        /// </summary>
        /// <param name="xmlFileName">XML文档完全文件名(包含物理路径)</param>
        /// <param name="xpath">要匹配的XPath表达式(例如:"//节点名//子节点名")</param>
        /// <returns>返回XmlNodeList</returns>
        public static XmlNodeList GetXmlNodeListByXpath(string xmlFileName, string xpath)
        {
            XmlDocument xmlDoc = new XmlDocument();

            try
            {
                xmlDoc.Load(xmlFileName); //加载XML文档
                XmlNodeList xmlNodeList = xmlDoc.SelectNodes(xpath);
                return xmlNodeList;
            }
            catch (Exception ex)
            {
                return null;
                //throw ex; //这里可以定义你自己的异常处理
            }
        }