How to display an image or UIImage with an plain CALayer?

Question

I often read that using CALayer rather than UIImageView is an performance boost when it comes to heavy image usage. That makes sense, because UIImageView causes 3 copies of the image in memory, which is needed for Core Animation. But in my case I dont use Core Animation.

How could I assign an UIImage (or the image data of it) to an CALayer and then display it?

Answer 1

UIImage*    backgroundImage = [UIImage imageNamed:kBackName];
CALayer*    aLayer = [CALayer layer];
CGFloat nativeWidth = CGImageGetWidth(backgroundImage.CGImage);
CGFloat nativeHeight = CGImageGetHeight(backgroundImage.CGImage);
CGRect      startFrame = CGRectMake(0.0, 0.0, nativeWidth, nativeHeight);
aLayer.contents = (id)backgroundImage.CGImage;
aLayer.frame = startFrame;