Gradient mask on UIView

Question

I have a UIView and want to have the bottom part of it fade out to 0 opacity.

May this be done to a UIView (CALayer) in order to affect an entire UIView and its content?

Answer 1

Yes, you can do that by setting CAGradientLayer as your view's layer mask:

#import <QuartzCore/QuartzCore.h>

...

CAGradientLayer *maskLayer = [CAGradientLayer layer];

maskLayer.frame = view.bounds;
maskLayer.colors = @[(id)[UIColor whiteColor].CGColor, (id)[UIColor clearColor].CGColor];
maskLayer.startPoint = CGPointMake(0.5, 0);
maskLayer.endPoint = CGPointMake(0.5, 1.0);

view.layer.mask = maskLayer;

P.S. You also need to link QuartzCore.framework to your app to make things work.