iphone – 如何获取应用程序购买中的所有标识符

以下代码用于一个产品.

- (void)viewDidLoad {
[super viewDidLoad];


if ([SKPaymentQueue canMakePayments]) {
        NSLog(@"Parental-controls are disabled");

        SKProductsrequest *productsrequest = [[SKProductsrequest alloc] initWithProductIdentifiers:[NSSet setWithObject:@"com.companion.onemonth"]];
        productsrequest.delegate = self;
        [productsrequest start];
    } else {
        NSLog(@"Parental-controls are enabled");
        //com.companion.onemonth ;
    }
}


    - (IBACtion)purchase {
    SKPayment *payment = [SKPayment paymentWithProductIdentifier:@"com.companion.onemonth"];
    [[SKPaymentQueue defaultQueue] addtransactionObserver:self];
    [[SKPaymentQueue defaultQueue] addPayment:payment];
}

通过这个代码,我可以得到一个产品,但不知道如何在运行时获取多个标识符.