calling a specific method when viewcontroller is resigned

Question

I have two view controllers: RootViewController and DetailViewController

I define a Push Segue to DetailViewController from RootViewController in Storyboard, and I set its ID to ShowDetailView. I can then set up various variables in DetailViewController using the method

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([[segue identifier] isEqualToString:@"ShowDetailView"]) {
    }
}

My Question: Is there a way to call a method (performed in RootViewController) when I resign from DetailViewController back to RootViewController? I'm using the following code to resign:

[self.navigationController popViewControllerAnimated: YES];

i think you can make PushViewControllerAnimated it will help — YasBES, Jul 31 '13 at 01:22
A method of what class do you have in mind? The call of `[self.navigationController popViewControllerAnimated: YES];` is part of some method that executes before you return the control, but I understand that you need something else. Please clarify. — Sergey Kalinichenko, Jul 31 '13 at 01:22
@Auser Does [this answer](http://stackoverflow.com/q/6203799/335858) give you what you are looking for? — Sergey Kalinichenko, Jul 31 '13 at 01:34
@dasblinkenlight I suppose it does, if declaring a delegate is the easiest and best way to about doing this. Thanks for the reference. — Apollo, Jul 31 '13 at 01:36
@Auser There is [an alternative solution without a delegate](http://stackoverflow.com/a/12524742/335858). — Sergey Kalinichenko, Jul 31 '13 at 02:06

Lucas Eduardo · Answer 1 · 2013-07-31T01:41:37.487

By default? No. You can build a delegate for this.

But instead, I think you can perform the code you want inside -(void)viewWillAppear:(BOOL)animated of your RootViewController.

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

    [self myMethodHere];
}

The viewWillAppear method will be called exactly after your DetailViewController will be resigned.

EDIT: Like a said, no easy way to do this. Maybe the best way its really with a delegate. It really has to be AFTER the resign? If it can be before, you can get the reference of your rootViewController and execute your method BEFORE the resign, like this:

 RootViewController *rootViewController = (RootViewController*) [[self.navigationController viewControllers] objectAtIndex:0];
[rootViewController someMethod];
[self.navigationController popViewControllerAnimated: YES];

If you really want to be after, than you can create a flag and set to yes with the code above, and check this flag with an if inside viewWillAppear to execute your method, otherwise you cannot run from delegate.

the problem with that is that every time the view appears, this method will get called. That's inefficient if I only want the method to be called when I resign from DetailViewController. — Apollo, Jul 31 '13 at 01:28

calling a specific method when viewcontroller is resigned

1 Answers1