Question

I’m having a problem in my application with an EXC_BAD_ACCESS after receiving a memory warning.
This is how I’m testing:
I wrote a simple application that just allocates memory but doesn’t free it. After I allocated a lot of memory leaving only about 14 MB free memory, I switch to my main application. Immediately I receive a memory warning in didReceiveMemoryWarning. Moments later my app crashes in a function that sets an image in an UIButton:

-(void)activateRecordButton
{
    UIImage *image = [UIImage imageNamed:@"audioRecordOn"];
    [recButton setImage:image forState:UIControlStateNormal];
}

The error I get is EXC_BAD_ACCESS(code=1, address=some_address) on the line which calls setImage.
If I comment these lines, my app crashes in an another function that sets an image for a UIButton.

This is my didReceiveMemoryWarning:

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

Why is this happening? Is this because there is no more memory to load the images or because recButton was deallocated somehow, when the other app allocated a lot of memory?

I’m running on an Iphone 4 ios 5.1.1

Answer 1

A UIViewController will by default release its view in didReceiveMemoryWarning (if possible). Your button will also be released if you didn’t retain it manually.

setImage is then called on a nonexistent object and this will trigger a EXC_BAD_ACCESS.