Question

I have an XML file that I need to apply a namespace to at runtime. I’ve searched the net and most examples seem to suggest using the “SetAttributeValue” function. When I use the code below it throws an exception when I try to “ToString()” with the following error:

The prefix '' cannot be redefined from '' to 'http://schemas.datacontract.org/2004/07/' within the same start element tag.

Any ideas what is going wrong?

XDocument data = XDocument.Parse("<Root><Stuff>Test</Stuff></Root>");

string ns = "http://schemas.datacontract.org/2004/07/";

data.Root.SetAttributeValue("xmlns",ns);

SaveFile(data.ToString());

Answer 1

You can’t do that. Namespaces are fundamental to the DOM. The only way I can think of right now is to add it using String.Replace on the entire XML text and then reparse the result.