Intercept back navigation in iOS7

Question

I want to stop somebody going back on my Navigation Controller if they haven't saved their changes. Most posts on SO discuss overriding the back button (with a variety of techniques to do this). However, iOS7 allows you to now swipe to go back in a navigationViewController...

I did see the UINavigationControllerDelegate which looks like the right type of delegate I'd want to implement but I see no way to cancel a navigation action. Any ideas how to do this?

http://stackoverflow.com/a/17213640/3226583 – manya Jan 24 '14 at 09:27 — manya, Jan 24 '14 at 09:27

Tarek Hallak · Answer 1 · 2013-09-30T03:18:36.057

1

Unfortunately nothing changed in iOS7, you still need to fake your back button if you want to put some check into it.

By the way it easier now since you don't need to fake the arrow button.

Edit:

to do that:

UIButton *backButton = [[UIButton alloc] initWithFrame: CGRectMake(0, 0, 44.0f, 30.0f)];
[backButton setImage:[UIImage imageNamed:@"back.png"]  forState:UIControlStateNormal];
[backButton addTarget:self action:@selector(popVC) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];

edited Sep 30 '13 at 03:18

answered Sep 23 '13 at 04:51

Tarek Hallak

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but how do I intercept the screen edge drag (new in iOS7)? That doesn't use the button does it? – ConfusedNoob Sep 29 '13 at 20:54
you just replace the left backBarButtom nothing more. – Tarek Hallak Sep 30 '13 at 03:15
you may want to detect back gesture start in method added to your UIGestureRecognizer (use addTarget message) and show alert from it. probably this would break the gesture – Mix Mar 14 '14 at 19:56
another option is to disable back gestures at all – Mix Mar 14 '14 at 19:57

Intercept back navigation in iOS7

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