var scheme = Request.Url.Scheme; // will get http, https, etc.
var host = Request.Url.Host; // will get www.mywebsite.com
var port = Request.Url.Port; // will get the port
var path = Request.Url.AbsolutePath; // should get the /pages/page1.aspx part, can't remember if it only get pages/page1.aspx
Uri uri = Context.Request.Url;
var scheme = uri.Scheme // returns http, https
var scheme2 = uri.Scheme + Uri.SchemeDelimiter; // returns http://, https://
var host = uri.Host; // return www.mywebsite.com
var port = uri.Port; // returns port number