iphone - How to mask a UIView

Question

I'm working on an app where I draw a UIView via code and I fill it with a UIColor. Next thing I want to load a mask.png file (no transparency, just black and white) and mask the UIView to change its visual appearance.

Any idea how to do this?

Answer 1

// Create your mask layer
CALayer* maskLayer = [CALayer layer];
maskLayer.frame = CGRectMake(0,0,yourMaskWidth ,yourMaskHeight);
maskLayer.contents = (__bridge id)[[UIImage imageNamed:@"yourMaskImage.png"] CGImage];

// Apply the mask to your uiview layer        
yourUIView.layer.mask = maskLayer;

Remember to import QuartzCore and add the framework

#import <QuartzCore/QuartzCore.h>

It is very easy but I didn't find the answer anywhere!