XPath query for XML node with colon in node name

What XPath query will select the <media:thumbnail /> node in the following XML?

<item>
  <title>Sublime Federer crushes Wawrinka</title>
  <description>Defending champion Roger Federer cruises past Stanislas开发者_运维问答 Wawrinka 6-1 6-3 6-3 to take his place in the Australian Open semi-finals.</description>
  <link>http://news.bbc.co.uk/go/rss/-/sport2/hi/tennis/9372592.stm</link>
  <guid isPermaLink="false">http://news.bbc.co.uk/sport1/hi/tennis/9372592.stm</guid>
  <pubDate>Tue, 25 Jan 2011 04:21:23 GMT</pubDate>
  <category>Tennis</category>
  <media:thumbnail width="66" height="49" url="http://news.bbcimg.co.uk/media/images/50933000/jpg/_50933894_011104979-1.jpg"/>
</item>

The XML came from this RSS feed.

You need to learn about namespaces and how to define/register a namespace in your XPath engine so that you can then use the associated prefix for names in that registered namespace. There are plenty of questions in the xpath tag asking how to use names that are in a namespace -- with good answers. Search for them.

A very rough answer (ignoring namespaces at all) is:

//*[name()='media:thumbnail']

What worked for me is:

/item/*[local-name()='thumbnail']

If you're looping an XmlNodeList array just use *[local-name()='thumbnail']