How do I set the contents of a CALayer to a CGImageRef?

Question

I want to set the contents of a CALayer to an image. The CALayer has a contents property The documentation on that property says that "a layer can set this property to a CGImageRef to display the image as its contents." But the property takes an id so in Xcode I get the following issue:

Semantic Issue: Incompatible pointer types assigning to 'id' from 'CGImageRef' (aka 'struct CGImage *')

How can I assign a CGImageRef to the contents property when it only takes an id? What am I missing here?

Answer 1

Instead of using (id) you can use (__bridge id) to solve the type convert issue.

Answer 2

Explicitly casting CGImageRef to id should fix the warning. For example,

CGImageRef imageRef;

...

layer.contents = (id) imageRef;

should be working fine.