关于读写XML文件
如我有一XML文件如下,我要如何读写其中userID和userName两个的值.   
  <?xml   version= "1.0 "   encoding= "utf-8 "?>  
  <configuration>  
        <appSettings>  
              <add   key= "userID "   value= "001 "   />  
              <add   key= "userName "   value= "admini "   />  
        </appSettings>  
  </configuration>    
------解决方案--------------------是web.config或app.config吗?   
 是的话读出来只要System.Configuration.ConfigurationSettings.AppSettings[ "userID "]就行了 
------解决方案--------------------写入貌似没有现成的方法,不过当它xml处理就行了。               
             XmlDocument doc = new XmlDocument(); 
             doc.Load( "c:\\test.xml ");   
             XmlNode node = doc.SelectSingleNode( "/configuration/appSettings/add[@key= 'userID '] ");   
             if (node != null) 
             { 
                 // 把userID 改成 002 
                 node.Attributes[ "value "].Value =  "002 "; 
             }   
             doc.Save( "c:\\test.xml ");
------解决方案--------------------try..   
 //读取 
             Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None); 
             Console.WriteLine(config.AppSettings.Settings[ "userID "].Value +  " :  " + config.AppSettings.Settings[ "userName "].Value); 
             //更改 
             config.AppSettings.Settings[ "userID "].Value =  "123 "; 
             config.AppSettings.Settings[ "userName "].Value =  "test "; 
             config.Save();
------解决方案--------------------这个对了   
 //读取 
 Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None); 
 Console.WriteLine(config.AppSettings.Settings[ "userID "].Value +  " :  " + config.AppSettings.Settings[ "userName "].Value);     
 //更改 
 config.AppSettings.Settings[ "userID "].Value =  "123 "; 
 config.AppSettings.Settings[ "userName "].Value =  "test "; 
 config.Save();