Checking if a UIViewController is about to get Popped from a navigation stack?

Question

I need to know when my view controller is about to get popped from a nav stack so I can perform an action.

I can\'t use -viewWillDisappear, because that gets called

Answer 1

You can observe the notification:

- (void)viewDidLoad{
    [super viewDidLoad];
    [NSNotificationCenter.defaultCenter addObserver:self selector:@selector(navigationControllerWillShowViewController:) name:@"UINavigationControllerWillShowViewControllerNotification" object:nil];
}

- (void)navigationControllerDidShowViewController:(NSNotification *)notification{
    UIViewController *lastVisible = notification.userInfo[@"UINavigationControllerLastVisibleViewController"];
    if(lastVisible == self){
        // we are being popped
    }
}