How to get notified of popped view in UINavigationController?

Question

I want to perform a action when the user pressed the back button on my UINavigationController when arrived at a certain UIViewController.

Unfortunately it looks like UINavigationControllerDelegate doesn't have any methods to get notified of the popping of views.

As a workaround I now have in the viewDidDisappear method my action, that only gets fired when animated is YES. This works, but it's a bit ugly.

How should I do this properly?

use viewWillDisappear for ur action if u want previously to know — Vijay-Apple-Dev.blogspot.com, Apr 06 '11 at 17:01

score 30 · Answer 1 · answered Mar 26 '14 at 10:38

The most popular way of handling a pop from navigation view controller (as well as from modal) is implementing viewWillDisappear for your view controller.

- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];

    if (self.isMovingFromParentViewController || self.isBeingDismissed) {
        // This view controller is being popped or dismissed
    }
}

score 5 · Answer 2 · edited Oct 26 '11 at 22:18

5

If you have a reference to the controller down the stack, the one which will show when this one is popped, you can register as a delegate and check it through

navigationController:willShowViewController:animated:

edited Oct 26 '11 at 22:18

Bo Persson

90,663
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answered Oct 25 '11 at 17:06

Max_B

59
1
2

score 0 · Answer 3 · answered Dec 23 '14 at 15:47

you can observe to the UINavigationControllerDelegate and check if transition will happened:

- (void)navigationController:(UINavigationController *)navigationController
          willShowViewController:(UIViewController *)viewController
                        animated:(BOOL)animated
    {
        if([navigationController.viewControllers containsObject:self])
        {
            NSLog(@"push");
        }
        else
        {
            NSLog(@"pop");
        }
    }

If you have a UITabBarController, you should use this solution because the viewWillDisappear is call each time you change the current tab index. — FouZ, Jun 13 '17 at 17:41

score 0 · Accepted Answer · answered Jun 28 '11 at 04:45

0

You can either call a delegate method when viewWillDisappear or set logic on viewWillAppear for certain UIViewController.

answered Jun 28 '11 at 04:45

alloc_iNit

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score 0 · Answer 5 · answered Jan 13 '21 at 15:07

First you need to conform UINavigationControllerDelegate to navigation controller and implement this method

 public func navigationController(
    _ navigationController: UINavigationController,
    didShow viewController: UIViewController,
    animated: Bool) {
    guard let dismissedViewController =
            navigationController.transitionCoordinator?
            .viewController(forKey: .from),
          !navigationController.viewControllers
            .contains(dismissedViewController) else {
        return
    }
    performOnDismissed(for: dismissedViewController)
}

In performOnDismissed func, you can check dismissedViewController, like

if (dismissedViewController is DesireViewController)

then, fire your method.

How to get notified of popped view in UINavigationController?

5 Answers5

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