如何利用C#在XML中添加节点
<?xml   version= "1.0 "   encoding= "utf-8 "?>  
  <root>  
        <person   id= "jan "   phone= "123456 "   />  
        <person   id= "pin "   phone= "452369 "   />  
        <person   id= "afu "   phone= "856932 "   />  
        <person   id= "zgmaike "   phone= "856321 "   />  
        <age>  
              <person   id= "jan "   age= "20 "   />  
              <person   id= "pin "   age= "26 "   />  
              <person   id= "afu "   age= "23 "   />  
        </age>  
  </root>    
 如何在“ <person   id= "afu "   age= "23 "   /> ”后添加上“ <person   id= "zgmaike "   age= "25 "   /> ”这个节点?
------解决方案--------------------http://www.pconline.com.cn/pcedu/empolder/net/0406/388296.html
------解决方案--------------------public static void AddXmlNode(string xml,string refid,string newid,string age) 
 { 
 XmlDocument xmldoc = new XmlDocument(); 
 xmldoc.Load(xml); 
 XmlNode refNode = null; 
 XmlNodeList xnl = xmldoc.SelectNodes( "/root/age/person "); 
 foreach (XmlNode node in xnl) 
 { 
 string attr = node.Attributes[ "id "].Value; 
 if (attr == refid)//查找节点的id是否等于你输入的id 
 { 
 refNode = node;//找到你要的节点 
 break; 
 } 
 } 
 XmlNode parent = xmldoc.SelectSingleNode( "/root/age "); 
 XmlElement newNode = xmldoc.CreateElement( "person "); 
 parent.InsertAfter(newNode,refNode);//在你所选的节点后新增节点 
 newNode.SetAttribute( "id ",newid); 
 newNode.SetAttribute( "age ",age); 
 xmldoc.Save(xml); 
 }