Drawing a transparent circle on top of a UIImage - iPhone SDK

Question

I am having a lot of trouble trying to find out how to draw a transparent circle on top of a UIImage within my UIImageView. Google-ing gives me clues, but I still can\'t find a

Answer 1

Easiest way is simply to create a semi-transparent square UIView, then set the cornerRadius of its layer to be half of its width/height. Something like:

UIView *squareView = [[UIView alloc] initWithFrame:CGRectMake(0,0,100,100)];
squareView.alpha = 0.5;
squareView.layer.cornerRadius = 50;
...
[squareView release];