Get url without querystring
You can use System.Uri
Uri url = new Uri("http://www.example.com/mypage.aspx?myvalue1=hello&myvalue2=goodbye");
string path = String.Format("{0}{1}{2}{3}", url.Scheme,
Uri.SchemeDelimiter, url.Authority, url.AbsolutePath);
Or you can use substring
string url = "http://www.example.com/mypage.aspx?myvalue1=hello&myvalue2=goodbye";
string path = url.Substring(0, url.IndexOf("?"));
EDIT: Modifying the first solution to reflect brillyfresh's suggestion in the comments.
Here's a simpler solution:
var uri = new Uri("http://www.example.com/mypage.aspx?myvalue1=hello&myvalue2=goodbye");
string path = uri.GetLeftPart(UriPartial.Path);
Borrowed from here: Truncating Query String & Returning Clean URL C# ASP.net