ios - 在App Purchase中可以正常使用，但是付款成功后我无法更改UIButton图像

Question

我已经购买了应用程序，并且运行良好。这是我在InAppPurchaseObserver.m中拥有的内容:

case SKPaymentTransactionStatePurchased:
            // Item was successfully purchased!

            [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isProUpgradePurchased" ];
            [[NSUserDefaults standardUserDefaults] synchronize];

            [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
            break;

case SKPaymentTransactionStateRestored:
            // Verified that user has already paid for this item.
            // Ideal for restoring item across all devices of this customer.

            [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isProUpgradePurchased" ];
            [[NSUserDefaults standardUserDefaults] synchronize];

            [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
            break;

在我的ViewController中，我正在这样做:

if([[NSUserDefaults standardUserDefaults] boolForKey:@"isProUpgradePurchased"]) {

  [energeeButton setImage:[UIImage imageNamed:@"thumb_unlocked_off.png"] forState:UIControlStateNormal];

} 

在我重新启动应用程序后，该方法就可以工作，但是我希望在应用程序内购买完成后立即更改按钮图像。

我如何做到这一点？

谢谢!

Answer 1

当该值更改时，您需要向viewcontroller发送各种通知，以便它可以重新加载该特定图像

[[NSNotificationCenter defaultCenter] postNotificationName:@"DZCustomNotification" object:nil];
// put this right after you change the user defaults




// put this in the initializer of your viewcontroller
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(purchasedChanged:) name:@"DZCustomNotification" object:nil];

// create this instance method in your viewcontroller class

- (void)purchasedChanged:(NSNotification *)notif {
    if([[NSUserDefaults standardUserDefaults] boolForKey:@"isProUpgradePurchased"]) {

        [energeeButton setImage:[UIImage imageNamed:@"thumb_unlocked_off.png"] forState:UIControlStateNormal];

    }
}

有呀!