How to find if a file is fragmented or not?

I am w开发者_如何学Criting a piece of code in c#. I am looking for a way to find if a particular file on a volume is fragmented or not. i am not concerned with finding number of fragments of the file, but just only whether it is fragmented or not.

Thanks.

This blog post has a c# implimentation of the Defrag API for Windows:

http://blogs.msdn.com/b/jeffrey_wall/archive/2004/09/13/229137.aspx

It might be a good starting point.