iPhone App - dismissing modal view controller doesn't dealloc it

Question

I have a UIViewController (call it NumberTwo) which I presented as a modal view controller from another UIViewController (call it NumberOne). NumberTwo contains a touchesBegan method which listens for touches, and it also has an accelerometer method which listens for device orientation changes in the x, y, or z direction. NumberTwo has a button called "Done" which, when tapped, dismisses itself as a modal view controller:

[self dismissModalViewControllerAnimated:NO];

But it seems as though it's still listening for touches, and it's still listening for accelerations. How can I completely free up NumberTwo when I dismiss it? I tried adding a release call as follows:

[self dismissModalViewControllerAnimated:NO];
[self release];

but that caused a EXEC_BAD_ACCESS.

Answer 1

Did you release the controller after you presented it? Eg in your method in NumberOneController that presents it, do you have something like:

NumberTwoController * controller = [NumberTwoController alloc] init];
// do stuff to config controller
[self presentModalViewController: controller];
[controller release];

Unless you want to hang on to NumberTwoController for re-use, this would be the usual pattern. The presentModalViewController method ensures that the controller is retained while it's in use. It should then get tidied up when, within NumberTwoController , you call [self dismissModalViewControllerAnimated: NO] .

Answer 2

I had a very similar issue that plagued me for days. It turned out that my view controller class wasn't being deallocated when I dismissed it because that view controller had an active NSTimer that wasn't being invalidated (stopped). I was able to kill the timer in viewDidDisappear.

Answer 3

Make sure you are releasing everything you use when you finish with it; The dealloc method is only called when the UIViewController and all of its properties/objects are no longer in use. Never use [self release]; you need to release it from the view controller that created it after you are finished with it.