UIView performance: opaque, backgroundColor, clearsContextBeforeDrawing?

Question

I\'m displaying opaque PNGs with UIImageViews inside of a superview with a white background color. What\'s best for performance?

UIImageView D

Answer 1

Assuming that your PNGs always fills the entire UIImageView, you should get the best performance using:

opaque = YES, clearsContextBeforeDrawing = NO. In this mode backgroundColor is irrelevant. The pixels are simply replaced with the new image data.

For transparent PNGs on a single-color background, the fastest will be:

opaque = YES, clearsContextBeforeDrawing = YES, and backgroundColor matching whatever you need. In this case [UIColor whiteColor].