C#中读取xml文件指定节点

• 01.class Program  
  02.   {  
  03.       static void Main(string[] args)  
  04.       {  
  05.           XMLOperation xmlOpr = new XMLOperation();  
  06.           XmlNode xn=xmlOpr.getXmlNode("activity.xml", "2");  
  07.           string ActivityId = (xn.SelectSingleNode("ActivityId")).InnerText;  
  08.           string ActivityName = (xn.SelectSingleNode("ActivityName ")).InnerText;  
  09.           string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;  
  10.           Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);  
  11.           Console.Read();  
  12.       }  
  13.   }  

  XmlDocumentSelectSingleNode方法的使用
• XmlDocumentSelectNodes方法的使用
• 通过节点属性查找指定节点

假设xml文件内容是:

<?xml version="1.0" encoding="utf-8"?>  
<Workflow>  
  <Activity>  
    <ActivityId>1</ActivityId>  
    <ActivityName>start</ActivityName>  
    <BindingPageId>1</BindingPageId>  
    <BindingRoleId>1</BindingRoleId>  
    <ActivityLevel>1</ActivityLevel>  
  </Activity>  
  <Activity>  
    <ActivityId>2</ActivityId>  
    <ActivityName>pass</ActivityName>  
    <BindingPageId>2</BindingPageId>  
    <BindingRoleId>2</BindingRoleId>  
    <ActivityLevel>2</ActivityLevel>  
  </Activity>  
</Workflow>  

我们需要读取Activity节点下的内容，因为存在多个Activity，所以需要读取多个节点。可以使用 XmlDocument.SelectSingleNode和XmlDocument.SelectNodes方法查找节点。前一个是查找匹配的第一个节点，而后一个则会返回一个节点列表。

1.XmlDocument.SelectSingleNode方法的使用

首先创建一个读取xml文件的方法ReadXmlNode

01./// <summary>    
02.      /// 读取xml中的指定节点的值  
03.      /// </summary>    
04.      public void ReadXmlNode(string filename)  
05.      {  
06.          XmlDocument xmlDoc = new XmlDocument();  
07.          try  
08.          {  
09.              xmlDoc.Load(filename);  
10.              //读取Activity节点下的数据。SelectSingleNode匹配第一个Activity节点  
11.              XmlNode root = xmlDoc.SelectSingleNode("//Activity");//当节点Workflow带有属性是，使用SelectSingleNode无法读取          
12.              if (root != null)  
13.              {  
14.                  string ActivityId = (root.SelectSingleNode("ActivityId")).InnerText;  
15.                  string ActivityName = (root.SelectSingleNode("ActivityName ")).InnerText;  
16.                  string ActivityLevel = root.SelectSingleNode("ActivityLevel").InnerText;  
17.                  Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);  
18.              }  
19.              else  
20.              {  
21.                  Console.WriteLine("the node  is not existed");  
22.                  //Console.Read();  
23.              }  
24.          }  
25.          catch (Exception e)  
26.          {  
27.              //显示错误信息  
28.              Console.WriteLine(e.Message);  
29.          }  
30.      }  

然后在主函数中调用该方法

01.class Program  
02.   {  
03.       static void Main(string[] args)  
04.       {  
05.           XMLOperation xmlOpr = new XMLOperation();  
06.           xmlOpr.ReadXmlNodes("activity.xml");  
07.           Console.Read();  
08.       }  
09.   }  

输出结果为：

共有2个节点 ActivityId:  1 ActivityName:  start ActivityLevel:  1 ActivityId:  2 ActivityName:  pass ActivityLevel:  2

3.通过节点属性查找指定节点

参考http://www.csharp-examples.net/xml-nodes-by-attribute-value/，虽然没有用到参考文章中的方法，不过总觉得以后会用到的。

01./// <summary>    
02.     ///通过ActivityLevel获取xmlnode，需要保证ActivityLevel在一个xml文档中是唯一的。  
03.     /// </summary>    
04.     public XmlNode getXmlNode(string filename, string activitylevel)  
05.     {  
06.         XmlDocument xmlDoc = new XmlDocument();  
07.         try  
08.         {  
09.             xmlDoc.Load(filename);  
10.             XmlNodeList xnList = xmlDoc.SelectNodes("//Activity");//当节点Workflow带有属性是，使用SelectSingleNode无法读取          
11.             foreach (XmlNode xn in xnList)  
12.             {  
13.                 string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;  
14.                 if(activitylevel==ActivityLevel)  
15.                 {  
16.                     return xn;  
17.                 }  
18.             }  
19.         }  
20.         catch (Exception e)  
21.         {  
22.             //显示错误信息  
23.             Console.WriteLine(e.Message);  
24.         }  
25.         return null;  
26.     }  

然后在主函数中调用该方法

01.class Program  
02.   {  
03.       static void Main(string[] args)  
04.       {  
05.           XMLOperation xmlOpr = new XMLOperation();  
06.           XmlNode xn=xmlOpr.getXmlNode("activity.xml", "2");  
07.           string ActivityId = (xn.SelectSingleNode("ActivityId")).InnerText;  
08.           string ActivityName = (xn.SelectSingleNode("ActivityName ")).InnerText;  
09.           string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;  
10.           Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);  
11.           Console.Read();  
12.       }  
13.   }  

输出结果为：

ActivityId:2 ActivityName:pass ActivityLevel:2

说明：本文出处：http://blog.csdn.net/xw13106209/article/details/6384218