28

在 iOS8 之前，我们使用 UIActionSheet 来显示警报，现在我们需要使用 UIAlertController。

当我们使用 UIActionSheet 时，我们可以通过将 clickedButtonAtIndex 与 cancelButtonIndex 进行比较来轻松处理用户在弹出窗口之外单击的情况（这意味着他想取消操作） - 如果用户确实在弹出窗口之外按下，我们得到取消按钮索引在这个函数中。

我们如何使用新的 UIAlertController 处理这些情况？我尝试使用“完成”块，但它没有任何上下文。有没有简单的方法来处理这个？（除了“保存”一些一般变量中的动作状态）。

4

3 回答 3

45

您可以使用 style:UIAlertActionStyleCancel 添加一个动作，当用户在弹出窗口外点击时，将调用此动作的处理程序。

if ([UIAlertController class]) {
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Alert Title" message:@"A Message" preferredStyle:UIAlertControllerStyleActionSheet];

    [alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
        NSLog(@"User clicked button called %@ or tapped elsewhere",action.title);
    }]];

    [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        NSLog(@"User clicked button called %@",action.title);
    }]];

    [alertController addAction:[UIAlertAction actionWithTitle:@"Other" style:UIAlertActionStyleDestructive handler:^(UIAlertAction *action) {
        NSLog(@"User clicked button called %@",action.title);
    }]];

    UIControl *aControl = (UIControl *) sender;
    CGRect frameInView = [aControl convertRect:aControl.bounds toView:self.view];
    alertController.popoverPresentationController.sourceRect = frameInView;
    alertController.popoverPresentationController.sourceView = self.view;
    alertController.popoverPresentationController.permittedArrowDirections = UIPopoverArrowDirectionAny;
    [self presentViewController:alertController animated:YES completion:nil];
}
于 2014-08-24T07:02:28.413 回答
16

适用于具有警报样式的 UIAlertController 的解决方案。只需将手势识别器添加到 alertController 超级视图。

    [self presentViewController: alertController
                   animated: YES
                 completion:^{
                     alertController.view.superview.userInteractionEnabled = YES;
                     [alertController.view.superview addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget: self action: @selector(alertControllerBackgroundTapped)]];
                 }];

- (void)alertControllerBackgroundTapped
{
    [self dismissViewControllerAnimated: YES
                             completion: nil];
}
于 2015-10-29T17:46:53.320 回答
1

UITapGestureRecognizer 对我不起作用，所以我使用了这种方式：

func addDismissControl(_ toView: UIView) {
    let dismissControl = UIControl()
    dismissControl.addTarget(self, action: #selector(self.dismissAlertController), for: .touchDown)
    dismissControl.frame = toView.superview?.frame ?? CGRect.zero
    toView.superview?.insertSubview(dismissControl, belowSubview: toView)
}

func dismissAlertController() {
    self.dismiss(animated: true, completion: nil)
}

func presentAlertController(title: String?, message: String?, preferredStyle: UIAlertControllerStyle,  handler: ((UIAlertAction) -> Swift.Void)? = nil, completion: (() -> Swift.Void)? = nil) {

    let alertController = UIAlertController(title: title, message: nil, preferredStyle: .actionSheet)
    alertController.addAction(UIAlertAction(title: "OK", style: .default) { (alertAction) -> Void in
        handler?(alertAction)
    })

    self.present(alertController, animated: true, completion: {
        self.addDismissControl(alertController.view)
        completion?()
    })
}

func someWhereInYourViewController() {
    // ...
    presentAlertController(title: "SomeTitle", message: "SomeMessage", preferredStyle: .actionSheet, handler: { (alertAction) -> Void in
        //do some action
    }, completion: {
        //do something after presentation
    })
    // ...
}
于 2017-07-04T15:43:58.770 回答