How to trim whitespace from a data-bound XML element in WPF using XPath?

How can the whitespace at the start and end of the content of an 开发者_StackOverflowXML element be removed when binding to the element using XPath in WPF?

Assuming you mean something like:

<x:XData>
   <foo>     Bar    </foo>
</x:Data>

then there's no whitespace to trim here. Whitespace immediately following the opening tag, and immediately preceding the closing tag, is insignificant, and will be ignored anyway.