c# - Paypal IPN sample code has no ActionResult. How am i meant to give a url if there is no view? -

this paypals sample code ipn. have been on few days , getting no where. not sure meant call. in previous question asked said dont call receive method. lead me on think how paypal know go. (i.e method use.)

public class ipncontroller : controller {     [httppost]     public httpstatuscoderesult receive()     {         //store ipn received paypal         logrequest(request);          //fire , forget verification task         task.run(() =>  verifytask(request));          //reply 200 code         return new httpstatuscoderesult(httpstatuscode.ok);     }      private void verifytask(httprequestbase ipnrequest)     {         var verificationresponse = string.empty;          try         {             var verificationrequest = (httpwebrequest)webrequest.create("https://www.sandbox.paypal.com/cgi-bin/webscr");              //set values verification request             verificationrequest.method = "post";             verificationrequest.contenttype = "application/x-www-form-urlencoded";             var param = request.binaryread(ipnrequest.contentlength);             var strrequest = encoding.ascii.getstring(param);              //add cmd=_notify-validate payload             strrequest = "cmd=_notify-validate&" + strrequest;             verificationrequest.contentlength = strrequest.length;              //attach payload verification request             var streamout = new streamwriter(verificationrequest.getrequeststream(), encoding.ascii);             streamout.write(strrequest);             streamout.close();              //send request paypal , response             var streamin = new streamreader(verificationrequest.getresponse().getresponsestream());             verificationresponse = streamin.readtoend();             streamin.close();          }         catch ( exception exception)         {             //capture exception manual investigation         }          processverificationresponse(verificationresponse);     }       private void logrequest(httprequestbase request)     {         // persist request values database or temporary data store     }      private void processverificationresponse(string verificationresponse)     {         if (verificationresponse.equals("verified"))         {             // check payment_status=completed             // check txn_id has not been processed             // check receiver_email primary paypal email             // check payment_amount/payment_currency correct             // process payment         }         else if (verificationresponse.equals("invalid"))         {             //log manual investigation         }         else         {             //log error         }     } } 

there no actionresult how meant give url. thought of seems return invalid

public actionresult ipn() {     receive()   } 

i have asked previous questions still cant seem head around ipn.