Question

For testing not/retina display I’ve created an UIView with size 100×100.

I’ve create 2 images:
– normal size (100×100)
– retina size (200×200)

I have two situations:
1) Non-Retina display + Normal Size image in background
2) Retina display + Retina Size image in background

The 1st scenario is ok.
In the 2nd scenario the image is double size and in my UIView I can see only 1/4 of the total image.

The same happens when I try to assign a background image to my UIViewController navigation bar as following:

if (IS_RETINA()) {
    [self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:IMG_NAVIGATION_BAR_BACKGROUND_RETINA] forBarMetrics:UIBarMetricsDefault];
}
else {
    [self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:IMG_NAVIGATION_BAR_BACKGROUND] forBarMetrics:UIBarMetricsDefault];
}

Answer 1

There’s a much easier way to do this. Give the retina version of the image the same name as the non-retina version, except with a “@2x” at the end. For example, if your regular image was named foo.png, then the retina version should be named [e-mail].

Then, just refer to the regular version of the filename (e.g., foo.png) at all times. When your app is running on non-retina hardware the regular image will be used, but whenever you’re on retina hardware the higher-resolution image will be used automatically. It’s easier than having to write an if statement for every image you use, plus it’ll actually work.