receive.cs

        public ActionResult Receive()
        {
            var query = Request.QueryString;

            _logWriter.WriteLine(Request.RawUrl);

            if (query["hub.mode"] == "subscribe" &&
                query["hub.verify_token"] == "myToken874523")
            {
                //string type = Request.QueryString["type"];
                var retVal = query["hub.challenge"];
                return Json(int.Parse(retVal), JsonRequestBehavior.AllowGet);
            }
            else
            {
                return HttpNotFound();
            }
        }