如何防止UINavigation栏上的同时按钮触摸导致双重动作？

Question

In a UINavigation bar, there is a right custom share UIBarButtonItem and a back button in the left UIBarButtonItem. When simultaneously tapping on both buttons, the app produces a black view, possibly because both buttons are attempting to display a new view simultaneously - the share button presents a UIActivityViewController and the back button a VC from the prior screen.

In looking through similar questions here, I've tried the following solutions but neither prevented a black view from appearing on a simultaneous button touch:

1. Inserting exclusiveTouch into ViewDidLoad in the following 2 ways

a) for(UIView *temp in self.navigationController.navigationBar.subviews) { [temp setExclusiveTouch:YES]; } for(UIView *temp in self.navigationController.navigationBar.subviews) { [temp setExclusiveTouch:YES]; }

b) [self.navigationController.navigationBar setExclusiveTouch:YES];

2. Applying self.navigationController.navigationBar.userInteractionEnabled = NO; after a touch.

Are there other solutions?

Is this related to multi-threading?

Answer 1

In each touch event handler, add the following line:

[[UIApplication sharedApplication] beginIgnoringInteractionEvents];

When the handler has completed, execute the following:

[[UIApplication sharedApplication] endIgnoringInteractionEvents];

It's up to you to figure out what to consider the end of the handler. If you're pushing or popping view controllers, you might add that second line to the viewWillAppear of the relevant view controllers. If you're displaying a modal view controller, you can use the completion handler of -[UIViewController presentViewController:animated:completion:] .

Answer 2

Pretty much simple you can use make use of ExclusiveTouch property in this case

[self.navigationController.navigationBar setExclusiveTouch:YES];

This is a Boolean value that indicates whether the receiver handles touch events exclusively.

Setting this property to YES causes the receiver to block the delivery of touch events to other views in the same window. The default value of this property is NO.

Answer 3

If you want only one button to respond to touches at a time, you need to set exclusiveTouch for that button, rather than for the parent view.

Put this just after you add your bar button items.

for(UIView *temp in self.navigationController.navigationBar.subviews)
{
    [temp setExclusiveTouch:YES];
}

or you can set exclusiveTouch individually for each UIBarButton while creating them.