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语句跳转到此案例标签

我多次使用switch语句;这是我第一次看到这个。代码已从教程（here）中复制，我正在尝试为我的应用程序进行调整。希望得到这方面的帮助。 SD

Answer 1

C不是Swift。如果您使用花括号围绕所有案例内部构建switch语句，例如this，那么您会更高兴：

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

额外的花括号允许你做一些你不能做的事情。

造成这种情况的原因是：无法从switch语句跳转到此case标签

1 个答案: