How to Autorelease a CGImageRef?

Question

I have a method that returns a CGImageRef object. It contains this call:

CGImageRef posterFrame = [avAssetImage copyCGImageAtTime:time actualTim         


        

Answer 1

If you're using garbage collection, use CFMakeCollectable(posterFrame). If you're using traditional memory management, it's very straightforward:

return (CGImageRef)[(id)posterFrame autorelease];

You cast the CFTypeRef (in this case, a CGImageRef) to an Objective-C object pointer, send it the -autorelease message, and then cast the result back to CGImageRef. This pattern works for (almost) any type that's compatible with CFRetain() and CFRelease().