造成这种情况的原因是:无法从switch语句跳转到此case标签

Question

这是一个switch语句,我收到错误:

        switch (transaction.transactionState) {

        case SKPaymentTransactionStatePurchasing:

            // show wait view here
            statusLabel.text = @"Processing...";
            break;

        case SKPaymentTransactionStatePurchased:

            [[SKPaymentQueue defaultQueue] finishTransaction:transaction];

            // remove wait view and unlock iClooud Syncing
            statusLabel.text = @"Done!";

            NSError *error = nil;
            [SFHFKeychainUtils storeUsername:@"IAPNoob01" andPassword:@"whatever" forServiceName: kStoredData updateExisting:YES error:&error];

            // apply purchase action  - hide lock overlay and
            [oStockLock setBackgroundImage:nil forState:UIControlStateNormal];

            // do other thing to enable the features

            break;

        case SKPaymentTransactionStateRestored:

            [[SKPaymentQueue defaultQueue] finishTransaction:transaction];

            // remove wait view here
            statusLabel.text = @"";
            break;

        case SKPaymentTransactionStateFailed:

            if (transaction.error.code != SKErrorPaymentCancelled) {
                NSLog(@"Error payment cancelled");
            }
            [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
            // remove wait view here
            statusLabel.text = @"Purchase Error!";
            break;

        default:
            break;
    }

最后两种情况加上默认情况会给我以下错误:

无法从switch语句跳转到此case标签

我多次使用switch语句; 这是我第一次看到这个.代码已从教程(此处)复制,我正在尝试为我的应用程序进行调整.非常感谢这一方面的帮助.SD

Answer 1

C不是Swift.如果您switch使用花括号围绕所有案例内部构建语句,您会更高兴,如下所示:

switch (tag) {
    case 1: { // curly braces
        // ...
        break;
    }
    case 2: {  // curly braces
        // ...
        break;
    }
    case 3: {  // curly braces
        // ...
        break;
    }
}

额外的花括号可以让你做一些你不能做的事情.