UIViews firing an action in another UIViewController

Question

Hi

My iPhone app is made of of a main tabController with 4 main tabs. I have a situation where ViewController A loads ViewController B (using pushViewController). I now need to get back to ViewController A and and trigger an action on A from B.

Getting back to A is easy all I have to do is :-

self.tabBarController.selectedIndex = 0;
[self.navigationController popViewControllerAnimated:YES];

this then causes the ViewController A to be visible.

But how do I then get ViewController B to fire an action on A?

I have tried to use:-

ViewControllerA  *aVC = ((ViewControllerA *)((UIViewController *)[self.tabBarC.tabBarController.viewControllers objectAtIndex:0]));
[aVC setAnnoSelected];

Only when I do that I get:-

-[UINavigationController setAnnoSelected]: unrecognized selector sent to instance 0x461d290

I have tried to use

[ViewControllerA performSelector:@selector(setAnnoSelected) withObject: nil afterDelay: 0.0];

But so far no joy.

Any ideas would be greatly appreciated.

Thanks Cheryl

P.S. This is a great site for help - thanks to anyone who has ever answered a question as you have helped me too.

Answer 1

It looks like your tabBarController's viewControllers are actually UINavigationControllers (you can see this by the unrecognized selector error). You probably want to look at that controller's own view controllers:

UINavigationController   *navController = (UINavigationController *) [self.tabBarController.viewControllers objectAtIndex: 0];
ViewControllerA          *controller = [navController.viewControllers objectAtIndex: 0];

[controller setAnnoSelected];

You might want to consider doing this with a notification instead, however, as this method is a little fragile.