UIAlertController在外部点击时处理解除(IPad)

Question

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外点击的情况(这意味着他想要取消操作) - 如果用户确实在弹出窗口外按下了取消按钮索引在这个功能.

我们如何使用新的UIAlertController处理这些情况？我试图使用"完成"块,但它没有任何上下文.有一个简单的方法来处理这个？(除了"保存"某些一般变量中的动作状态).

Answer 1

您可以使用样式添加动作:UIAlertActionStyleCancel,当用户点击弹出窗口外,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];
}

Answer 2

适用于UIAlertController并具有警报风格的解决方案.只需要为alertController superview添加手势识别器.

    [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];
}