// 13.监听购买结果

• (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transaction{
  for(SKPaymentTransaction *tran in transaction){

    switch (tran.transactionState) {
        case SKPaymentTransactionStatePurchased:
            NSLog(@"交易完成");
            [[SKPaymentQueue defaultQueue] finishTransaction:tran];
  
            break;
        case SKPaymentTransactionStatePurchasing:
            NSLog(@"商品添加进列表");
            break;
        case SKPaymentTransactionStateRestored:
            NSLog(@"已经购买过商品");
            [[SKPaymentQueue defaultQueue] finishTransaction:tran];
            break;
        case SKPaymentTransactionStateFailed:
            NSLog(@"交易失败");
            [[SKPaymentQueue defaultQueue] finishTransaction:tran];
            break;
        default:
            break;
    }
  

  }
  }
  就是 [[SKPaymentQueue defaultQueue] finishTransaction:tran];除了 case SKPaymentTransactionStatePurchasing:
  NSLog(@"商品添加进列表");
  break;
  这里不需要之外都要加入的。

不然在你重复购买的时候就会提示你已经购买过的提示框了