OK, i was recently switch to .NET framework 4.5 and start using HttpClient instead of HttpWebRequest & Response. I really love that async/await style but i don't know how to get the redirected url after a POST / GET request.
With HttpWebResponse i can use .ResponseUri attribute
HttpWebRequest request = (HttpWebRequest)WebRequest.Create ("http://www.google.com");
HttpWebResponse response = (HttpWebResponse)request.GetResponse ();
string responseURI = response.ResponseUri;
Took me 3 hours of searching and i still can't get it done:(