iPhone - removing an entire viewController, not just its view

Question

I'm not using a navigation controller or a tab bar controller, I'm not using the push/pop method or presenting views modally. In my main view controller, I am adding a view controller like so:

UIViewController *nextController;
nextController = [[GamePlayViewController alloc] initWithNibName:@"GamePlayView" bundle:nil];
[nextController performSelector:@selector(setDelegate:) withObject:self];

temporaryController = nextController;

[self.view addSubview:nextController.view];

This view controller follows a delegate protocol and when the user is finished in this game view, this code is called:

[delegate backToMenu:self];

which calls this function in the app's main view controller:

- (void)backToMenu:(GamePlayViewController *)sender {
    NSLog(@"back to menu");

    [temporaryController.view removeFromSuperview];
}

Removing the view with removeFromSuperview seems to get rid of the view only, but I can see due to NSLogging that code is still executing in the .m file of that removed view. The view is still in in the app's memory. It has not been discarded as I had hoped.

"Release" is an old relic never to be used with ARC, so how can I entirely remove the viewController that was created with alloc/initWithNibName?

Thanks!

How is temporaryController defined? If it's a strong property, the answer may be as simple as setting it to nil. — Phillip Mills
@PhillipMills it is declared in my main view controller's header file: UIViewController *temporaryController; Setting it to nil was tried as part of the solution Rich provided below, but didn't change how that view still continues to run code — RanLearns

Rich Rich · Accepted Answer · 2014-04-12T21:43:45

You should also be using the view controller life cycle methods.

Adding:

GamePlayViewController *nextController = [[GamePlayViewController alloc] initWithNibName:@"GamePlayView" bundle:nil];
nextController.delegate = self;
[self addChildViewController:nextController];
[self.view addSubview:nextController.view];
[nextController didMoveToParentViewController:self];

temporaryController = nextController;

Removing:

[temporaryController didMoveToParentViewController:nil];
[temporaryController.view removeFromSuperview];
[temporaryController removeFromParentViewController];
temporaryController = nil;

Also if temporaryController is a strong property (or you've used an iVar), you should nil it out after removing it.

As the CAAnimation retains its delegate make you remove the animation and nil out the delegate.

-(void)didMoveToParentViewController:(UIViewController *)parentViewController
{
    [super didMoveToParentViewController:parentViewController];

    if (!parentViewController) {
        CAAnimation *animation = [movingObject.layer animationForKey:@"animatePositionX"];
        animation.delegate = nil;
        [movingObject.layer removeAnimationForKey:@"animatePositionX"];
    }
}

If you want to check your view controller is being deallocoated you should implement the dealloc method and place a breakpoint inside of it. I suggest a breakpoint over a NSLog as I don't know how much you already log out so it might get missed, with a breakpoint it is much clearly - actually stopping the program flow.

iPhone - removing an entire viewController, not just its view

1 Answers