How to remove all namespaces from XML with C#?

Question

I am looking for the clean, elegant and smart solution to remove namespacees from all XML elements? How would function to do that look like?

Defined interface:

Answer 1

And this is the perfect solution that will also remove XSI elements. (If you remove the xmlns and don't remove XSI, .Net shouts at you...)

string xml = node.OuterXml;
//Regex below finds strings that start with xmlns, may or may not have :and some text, then continue with =
//and ", have a streach of text that does not contain quotes and end with ". similar, will happen to an attribute
// that starts with xsi.
string strXMLPattern = @"xmlns(:\w+)?=""([^""]+)""|xsi(:\w+)?=""([^""]+)""";
xml = Regex.Replace(xml, strXMLPattern, "");