读取带有命名空间的xml的节点内容

Q：

Taking this simplifed example of my XML:

<?xml version="1.0"?> 
<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">
 <error>Invalid Login</error> 
</message>

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

XmlNode errorNode = oss.SelectSingleNode("/message/error"); 
if (errorNode != null)      
    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:

XmlNamespaceManager nsMgr = new XmlNamespaceManager(oss.NameTable); 
nsMgr.AddNamespace("ns", "http://www.mydomain.com/MyDataFeed");  
XmlNode errorNode = oss.SelectSingleNode("/ns:message/ns:error", nsMgr); 

 

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