ios - How do you show an UIAlertView above the Apple Pay PKPaymentAuthorizationViewController? -

using standard uialertview code below show alert underneath apple pay pkpaymentauthorizationviewcontroller sheet.

[[[uialertview alloc] initwithtitle:@"payment error"                             message:[error localizeddescription]                            delegate:nil                   cancelbuttontitle:@"okay"                   otherbuttontitles:nil] show]; 

how can show above payment authorization sheet? or there different way of presenting error messages apple pay? want give specific error messages when user enters invalid shipping address.

there's new callback in ios 11

public func paymentauthorizationcontroller(_ controller: pkpaymentauthorizationcontroller, didauthorizepayment payment: pkpayment, handler completion: (pkpaymentauthorizationresult) -> void) 

as can see, handler changes

completion: (pkpaymentauthorizationstatus) -> void) 

to

handler completion: (pkpaymentauthorizationresult) -> void) 

starting ios 11 status array of nserrors on completion handler.

have @ this year's session more details.