ios - Passing an objective-c protocol delegate as a parameter -

when pass objective-c protocol parameter, when , delegate used trigger 1 of methods, method not fire.

i'm using delegate paypal ios sdk defined follows:

@protocol paypalpaymentdelegate <nsobject>     - (void)paypalpaymentdidcancel:(paypalpaymentviewcontroller *)paymentviewcontroller; @end 

i have uiviewcontroller implements protocol:

//simpleviewcontroller.h @interface simpleviewcontroller : uiviewcontroller<paypalpaymentdelegate> 

and method signature following:

// helperfunctions.m + (void) dosomething: (id<paypalpaymentdelegate>)paypaldelegate {     // selector 'paypalpaymentdidcancel' fire     [paypaldelegate performselector:@selector(paypalpaymentdidcancel:) withobject:self] }   // called simpleviewcontroller.m implements paypalpaymentdelegate [helperfunctions dosomething: self] 

the problem when paypal returns result, not trigger delegate:

// code inside of 'success' block of afnetworking call paypalpaymentviewcontroller *paymentviewcontroller; paymentviewcontroller = [[paypalpaymentviewcontroller alloc] initwithpayment:payment                                                                  configuration:paypalconfiguration                                                                 delegate:paypaldelegate]; 

the paypaldelegate passed 'delegate' here never triggered paypal. whereas triggered if done simpleviewcontroller.m , not via method dosomething

once have created paymentviewcontroller keeping hold of paypaldelegate somewhere? paypalpaymentviewcontroller keeps weak reference delegate if not being released (and therefore none of it's methods firing) arc @ end of scope creates paypalpaymentviewcontroller.