造成这种情况的原因：无法从 switch 语句跳转到此 case 标签

Question

这是一个 switch 语句，我在其中遇到错误：

        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，给我以下错误：

Cannot jump from switch statement to this case label

switch 语句我已经用了很多很多次了；这是我第一次看到这个。代码是从教程 (here) 复制而来的，我正在尝试将其改编为我的应用程序。将不胜感激这方面的帮助。标准差

Answer 1

C 不是 Swift。如果您在所有案例内部使用花括号构建 switch 语句，您会更快乐，例如 this:

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

额外的花括号级别让您可以做其他方式做不到的事情。

造成这种情况的原因：无法从 switch 语句跳转到此 case 标签

What is causing this: Cannot jump from switch statement to this case label

objective-c

switch-statement

ios9