UIStackView Hide View Animation

Question

In iOS 11 the behaviour of the hide animation within a UIStackView has changed, but I have been unable to find this documented anywhere.

iOS 10

iOS 11

The code in both is this:

UIView.animate(withDuration: DiscoverHeaderView.animationDuration,                        delay: 0.0,                        usingSpringWithDamping: 0.9,                        initialSpringVelocity: 1,                        options: [],                        animations: {                             clear.isHidden = hideClear                             useMyLocation.isHidden = hideLocation                         },                        completion: nil) 

How do I restore the previous behaviour on iOS 11?

Answer 1

Just had the same issue. The fix is adding stackView.layoutIfNeeded() inside the animation block. Where stackView is the container of the items you're wishing to hide.

UIView.animate(withDuration: DiscoverHeaderView.animationDuration,                    delay: 0.0,                    usingSpringWithDamping: 0.9,                    initialSpringVelocity: 1,                    options: [],                    animations: {                         clear.isHidden = hideClear                         useMyLocation.isHidden = hideLocation                         stackView.layoutIfNeeded()                     },                    completion: nil) 

Not sure why this is suddenly an issue in iOS 11 but to be fair it has always been the recommended approach.