Question

Instruments is telling me that alot of memory is being allocated when I rapidly set the image name of a UIImageview in my app. I have a UIImageView that changes its image name every frame in my game. When profiled with zombie checking in instruments, the app seems to be constantly gaining live bytes at an enourmous rate. Is there a way that I can deallocate the UIImageView‘s current image to stop it from doing this? I am using ARC.

My code to assign the UIImageView‘s image is as follows:

aPlanet.image = [UIImage imageNamed:tempPlanetName];


Where aPlanet is the UIImageView and tempPlanetName is the name of the image. This is called every frame.

Answer 1

When you use UIImage imageNamed: it will load and cache that image file. This is intended for reuse of icons and other image resources that will be utilized more than once in your application.

Apart from it seeming somewhat unusual to update an image view with a new image every frame, you should look into alternative means of loading images that you will not need more than once – or even if you do, when you need more control over its lifecycle.

For example have a look at UIImage imageWithContentsOfFile: (documented here: Apple Developer Library Reference). It explicitly states that this method will not do any caching of the image contents.

I hope this helps you, but for every frame I doubt that your performance will be good enough with this approach, but this is probably the topic of a different question should the need arise.