Reditect url from the method of notify_url of paypal in mvc - asp.net-mvc-4

Question

i am using paypal for payment. in paypal i found two type url -
return_url
notify_url
i wan to check the validity after transaction, save some data and then redirect buyer to receipt page with a unique value that is saved in db. that is why i m not using redirect_url
here is my code
[HttpPost]
public ActionResult TestPaypalIpn()
{
var response = new StreamReader(Request.InputStream, System.Text.Encoding.UTF8).ReadToEnd();
var webClient = new WebClient();
string address = "https://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_notify-validate&" + response;
System.IO.File.WriteAllText(#"D:\Streamstech\Content\requestAddress.txt", address);
try
{
string result = webClient.DownloadString(address);
System.IO.File.WriteAllText(#"D:\Streamstech\Content\response.txt", result);
if (result == "VERIFIED")
{
if (Request.Params["payment_status"] == "Completed" && Request.Params["business"] == Request.Params["receiver_email"])
{
var lisenceKey = Request.Params["transaction_subject"];
var userProductLisence = UserProductLisenceRepository.GetConditional(
l => l.LisenceKey == lisenceKey).FirstOrDefault();
if (userProductLisence != null)
{
if (userProductLisence.PaypalTransactionId == null)
{
userProductLisence.PaypalTransactionId = Request.Params["txn_id"];
userProductLisence.PayerEmailForPaypalTransaction = Uri.EscapeUriString(Request.Params["payer_email"]);
UserProductLisenceRepository.Edit(userProductLisence);
return RedirectToAction("Receipt", "Transaction", new { requestId = userProductLisence.LisenceKey });
}
}
}
return RedirectToAction("ShowError", "Transaction", new { errorname = "", errorMessage = "something went wrong, try again later" });
}
return RedirectToAction("ShowError", "Transaction", new { errorname = "verification Problem", errorMessage = "Transaction not verified" });
}
catch (Exception e)
{
System.IO.File.WriteAllText(#"D:\Streamstech\Content\error.txt", e.Message);
return RedirectToAction("ShowError", "Transaction", new { errorname = "Error..!!!", errorMessage = "something went wrong, try again later" });
throw;
}
return null;
}
here i can compare, save data to database.. but it is not redirecting to receipt page.. what is the problem here in code...??
or any suggestion how can i do it.. ?
Thank You..

Answer 1

Based on your requirement, you need to use return_url instead of notify_url. For notify_url, it's used for receiving message in system back end and you maybe can't receive it immediately after payment is done. refer to https://developer.paypal.com/docs/classic/ipn/integration-guide/IPNPDTAnAlternativetoIPN/