Facebook C# SDK SignedRequest

There is no document on how to us开发者_开发技巧e Facebook C# SDK(http://facebooksdk.codeplex.com/) and I am trying to use FacebookSignedRequest.Parse method but it shows and error that its not defined . How do I use it ? I also need to extract values from signed request.

Thanks

This is how i do it to extract the signed request..

FacebookSignedRequest fbsign = FacebookSignedRequest.Parse(appsecret, Request.Form["signed_request"]);

And then assign it to a dynamic

dynamic result = fbsign.Data;