How to implement the Retina display in Application?

How to implement the Retina display in Application?

It’s mostly taken care of for you. Anytime you use the default UIKit views, you’ll automatically get a retina version. Text is also always rendered at retina resolution. And if you create a custom UIView and override drawRect, all the custom drawing you do with Core Graphics will be drawn at retina resolution (you just have to remember that in CG you are drawing with resolution-independent points).

Largely the only thing you have to do that’s special is that if you use PNG or JPEG graphics, you should supply a double-resolution version with a ”@2x” at the end of the name. So, for example in the “AudioRecorderPlayer” example where we have a 60×60 PlayButton.png, you’d also want to put a 120×120 PlayButton@2x.png in the project.

See points versus pixels in Apple’s online docs.