Question

我在我的应用上运行了这个代码，现在在iOS 6上它崩溃了我的应用程序：

// Another method
[NSThread detachNewThreadSelector:@selector(askServerForNFeID)
          toTarget:self withObject:nil];

- (void)askServerForNFeID {
    if ([response isEqualToString:@"XXXX"]) {
        NSString *responseMessage = [NSString stringWithFormat:
                                       NSLocalizedString(@"Autorizado o Uso da NFe\n para chave:\n%@", @""),
                                       [invoiceInfo NFeID]];

        UIAlertView *alert = [[UIAlertView alloc]
               initWithTitle:NSLocalizedString(@"Sefaz respondeu:", @"")
                     message:responseMessage
                    delegate:self
           cancelButtonTitle:NSLocalizedString(@"OK", @"")
           otherButtonTitles:nil];

        [alert show];
        [alert release];
    }
}

我已经知道从第二个线程调用警报会导致崩溃，因此我更改了代码以从主线程调用警报，如下所示：

if ([response isEqualToString:@"XXXX"]) {

    [self performSelectorOnMainThread:@selector(showAlertHelper:)
          withObject:[[NSArray alloc] initWithObjects:
            NSLocalizedString(@"Não posso seguir em frente", @""),
            NSLocalizedString(@"Você usou .....", @""), @"Fechar", @"Comprar", nil]
            waitUntilDone:YES];

注意我正在将标题，消息和按钮解析为showAlertHelper的列表......

-(void)showAlertHelper:(NSArray*)theArray{

    if ([[theArray objectAtIndex:3] isEqualToString:@""]) {
        UIAlertView *alertView = [[UIAlertView alloc]
              initWithTitle:[theArray objectAtIndex:0]
                    message:[theArray objectAtIndex:1]
                   delegate:nil
          cancelButtonTitle:[theArray objectAtIndex:2]
          otherButtonTitles:nil];
        [alertView show];
        [alertView release];
    }
    else {
        UIAlertView *alertView = [[UIAlertView alloc]
             initWithTitle:[theArray objectAtIndex:0]
                   message:[theArray objectAtIndex:1]
                  delegate:nil
         cancelButtonTitle:[theArray objectAtIndex:2]
         otherButtonTitles:[theArray objectAtIndex:3], nil];

        [alertView show];
        [alertView release];
    }
}

我现在的问题是，我有这个处理程序来捕获被点击的按钮，它不再起作用了。它没有被称为：

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    NSString *title = [alertView buttonTitleAtIndex:buttonIndex];

    if ([title isEqualToString:NSLocalizedString(@"Comprar", @"")]) {
        // Do stuff to buy credits...
    } else if ([title isEqualToString:NSLocalizedString(@"Fechar", @"")]) {
        NSLog(@"Fechar was selected.");
    }
    else if ([title isEqualToString:NSLocalizedString(@"Criar conta", @"")]) {
         // Do stuff to create an account...
    }
}

Answer 1

您从UIAlertView的创建方法中删除了委托

UIAlertView *alertView = [[UIAlertView alloc]
         initWithTitle:[theArray objectAtIndex:0]
               message:[theArray objectAtIndex:1]
              delegate:nil
     cancelButtonTitle:[theArray objectAtIndex:2]
     otherButtonTitles:[theArray objectAtIndex:3], nil];

应该是

UIAlertView *alertView = [[UIAlertView alloc]
         initWithTitle:[theArray objectAtIndex:0]
               message:[theArray objectAtIndex:1]
              delegate:self
     cancelButtonTitle:[theArray objectAtIndex:2]
     otherButtonTitles:[theArray objectAtIndex:3], nil];

Answer 2

问题在于，在重新编写的方法中，您将代理设置为nil而不是self。因此，不会调用alertView:clickedButtonAtIndex:委托方法。将代码更改为以下内容：在self参数中指定delegate:：

-(void)showAlertHelper:(NSArray*)theArray{

    if ([[theArray objectAtIndex:3] isEqualToString:@""]) {
        UIAlertView *alertView = [[UIAlertView alloc]
              initWithTitle:[theArray objectAtIndex:0]
                    message:[theArray objectAtIndex:1]
                   delegate:self
          cancelButtonTitle:[theArray objectAtIndex:2]
          otherButtonTitles:nil];
        [alertView show];
        [alertView release];
    } else {
        UIAlertView *alertView = [[UIAlertView alloc]
             initWithTitle:[theArray objectAtIndex:0]
                   message:[theArray objectAtIndex:1]
                  delegate:self
         cancelButtonTitle:[theArray objectAtIndex:2]
         otherButtonTitles:[theArray objectAtIndex:3], nil];

        [alertView show];
        [alertView release];
    }
}

检索UIAlertView上的tapped按钮

2 个答案: