How to get the method of backBarButtonItem of navigationItem?

Question

I have add the navigationItem.backBarButtonItem when turn to the new page like the following code , but I want to add a Timer for change some image before turn back to the first by backBarButtonItem.

    UIViewController *ReconnectView = [[AITReconnectView alloc] initWithNibName:@"AITReconnectView" bundle:nil] ;      
    ReconnectView.edgesForExtendedLayout = UIRectEdgeNone;          
    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:NSLocalizedString(@"Back", nil) style:UIBarButtonItemStyleBordered target:nil action:nil];               
   [self.navigationController pushViewController:ReconnectView animated:YES];

For example : When I click the backBarButtonItem , it will run the Timer for 3 second. And then turn back to the first view.

I have search for some information , but it only overwrite the new method for backBarButtonItem.

How to add a Timer in method of backBarButtonItem but retain the original method of backBarButtonItem ?

Thanks in advance.

Apple doesn't permit us handle event of `backBarButton`. You can make a backBarButton by yourself and set it to `leftBarButtonItem`, and handle event for it — Tony, Jun 20 '14 at 09:47
If the user expects to go back, why are you delaying the event? — Rambatino, Jun 21 '14 at 07:49
@MarkRamotowski I want to change image and show some information for user. — Martin, Jun 21 '14 at 07:51

score 2 · Accepted Answer · answered Jun 20 '14 at 09:15

2

There are two ways:

Create your own back button (similar like native) and selector method and assign it to button:

UIBarButtonItem *addButton = [[[UIBarButtonItem alloc] initWithTitle:@"BackToVcA"
                                                               style:UIBarButtonItemStyleBordered
                                                              target:self
                                                              action:@selector(addAction:)] autorelease];

self.navigationItem.rightBarButtonItem = addButton;

Use UIViewController life cycle method, viewWillDisappear or viewDidDisappear.

Hope this is what you're looking for.

answered Jun 20 '14 at 09:15

Mrunal

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I try to add a timer in `viewWillDisappear` or `viewDidDisappear`. But the view turn back to the first view and didn't wait for timer finish. When the view turn to the first view , the timer still count... – Martin Jun 21 '14 at 07:50
I know the first way which you post. But I don't know how to turn back to the first view by code. – Martin Jun 21 '14 at 07:55

viral · Answer 2 · 2014-06-20T09:24:33.963

0

If you want to delay the transition to the first view by 3 seconds, Just add, [NSThread sleepForTimeInterval:3.0]; to viewWillDisappearmethod of the second view.
If you want to execute method invocation in objective C, then [self performSelector:@selector(methodName) withObject:self afterDelay:3.0]; should work fine. Share code for some more information.

edited Jun 20 '14 at 09:24

answered Jun 20 '14 at 09:12

viral

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How to get the method of backBarButtonItem of navigationItem?

2 Answers2