How to fade a UIVisualEffectView and/or UIBlurEffect in and out?

Question

I want to fade a UIVisualEffectsView with a UIBlurEffect in and out:

var blurEffectView = UIVisualEffectView()
blurEffectView = UIVisualEffectView(effect: UI         


        

Answer 1

I just had this problem and the way I got around it was to house the UIVisualEffectsView in a UIView, and animate that UIView's alpha.

This worked well, except that it as soon as the alpha changed below 1.0 it turned to a solid white and looked very jarring. In order to get around this, you must set the UIView's layer property containerView.layer.allowsGroupOpacity = false and this will prevent it from flashing white.

Now you can animate in/fade out the UIView containing the visual effects view and any other subviews using it's alpha property and not have to worry about any graphical glitches or it logging a warning message.