在 UIAlertController 中按下返回按钮

Question

我正在尝试将UIAlertController 用于多种用途。它有两个按钮，取消和确定。我想将它添加到一个方法并返回按钮按下，所以我可以检查用户的响应并采取行动。

现在，我无法返回 block 内的值。那么，我该怎么做呢？

谢谢。

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"Atenção!", "Atenção!") message:NSLocalizedString(@"Você não finalizou a sua série. Se sair desta tela, irá zerar o cronômetro.", "") preferredStyle:UIAlertControllerStyleAlert];

    UIAlertAction *cancelar = [UIAlertAction actionWithTitle:NSLocalizedString(@"Cancelar", "Cancelar") style:UIAlertActionStyleCancel handler:^(UIAlertAction *action)
                               {
                                   [alertController dismissViewControllerAnimated:YES completion:nil];
                                   // I would like to return this button press to the method calling this one. 
                               }];
    [alertController addAction:cancelar];

    UIAlertAction *ok = [UIAlertAction actionWithTitle:NSLocalizedString(@"OK", "OK") style:UIAlertActionStyleDefault handler:^(UIAlertAction *action)
                               {
                                   [alertController dismissViewControllerAnimated:YES completion:nil];
                                   // I would like to return this button press to the method calling this one.
                               }];
    [alertController addAction:ok];

    [self presentViewController:alertController animated:YES completion:nil];

更新：实际使用

当用户按下back button时，它会调用一个方法来检查一个条件。如果满足条件，则会显示警报，用户需要决定是否离开屏幕。这就是为什么将答案返回给IBActionback Button 会很棒的原因。

注意：整个想法是有其他方法，除了back Button，也显示警报并获得用户的响应。

Answer 1

你可以利用积木。

创建这样的方法

- (void)alertWithResponse:(void (^)(BOOL didCancel))response {

    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"Atenção!", "Atenção!") message:NSLocalizedString(@"Você não finalizou a sua série. Se sair desta tela, irá zerar o cronômetro.", "") preferredStyle:UIAlertControllerStyleAlert];

    UIAlertAction *cancelar = [UIAlertAction actionWithTitle:NSLocalizedString(@"Cancelar", "Cancelar") style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {

                                   [alertController dismissViewControllerAnimated:YES completion:nil];
                                   response(YES);
                               }];
    [alertController addAction:cancelar];

    UIAlertAction *ok = [UIAlertAction actionWithTitle:NSLocalizedString(@"OK", "OK") style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {

                                   [alertController dismissViewControllerAnimated:YES completion:nil];
                                   response(NO);
                               }];
    [alertController addAction:ok];

    [self presentViewController:alertController animated:YES completion:nil];
}

现在在你的后退按钮中，像这样调用这个方法

- (IBAction)backButtonCliccked:(id)sender {

    //your button logic...
    //.
    //.
    //.
    [self alertWithResponse:^(BOOL didCancel) {
        if(didCancel) {
            //alert returned Cancel
        } else {
            //alert returned OK
        }
    }];
}