带有命名空间的xml节点如何读取

Q：

Taking this simplifed example of my XML:

1 <?xml version="1.0"?> 

2 <message xmlns="http://www.mydomain.com/MyDataFeed" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.mydomain.com/MyDataFeed https://secure.mydomain/MyDataFeed/myDataFeed.xsd" requestId="13898" status="1">

3  <error>Invalid Login</error> 

4 </message>

I am trying to select the 'error' node using SelectSingleNode method, however using the following code it always returns NULL?

1 XmlNode errorNode = oss.SelectSingleNode("/message/error"); 

2 if (errorNode != null)      

3     Console.Writeline("There is an error"); 

From research I have done this is related to namespaces but I simply can't get anything to work. Any advice?

 

A：

You're missing the XML namespace defined by the <message> node in your SelectSingleNode call. Assuming oss is an XmlDocument instance, you need to do this:

1 XmlNamespaceManager nsMgr = new XmlNamespaceManager(oss.NameTable); 

2 nsMgr.AddNamespace("ns", "http://www.mydomain.com/MyDataFeed");  

3 XmlNode errorNode = oss.SelectSingleNode("/ns:message/ns:error", nsMgr); 

 

From：http://stackoverflow.com/questions/1766254/selectsinglenode-always-returns-null

And:http://www.cnblogs.com/linlf03/archive/2011/11/30/2268705.html