Getting the current view controller from inside UINavigationControllerDelegate

Is there a way to get the view controller i'm transitioning out from inside :

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated

When I'm using navigationController.topViewControll开发者_运维技巧er I'm getting the one I'm moving into. Using the navigationController.viewControllers can suffice in case I'm getting deeper in the navigation system (cause I can look for the previous controller inside the array), but if I move "outside", this won't work, can the view controller I need is no longer there.

Any general way of doing it ? I need it so I can add to it a subview just during the animation, then of course it's gone.

Thanks

---

if you want to find a particular ViewController from array of navigation controller then try this.........

for(UIViewController * VC in [self.navigationController viewControllers])
{
    if([VC isKindOfClass:[ViewController class]])
    {
        //YOUR CODE ....... 
    }
}

Enjoy coding.........

---

I took a look a UINavigationControllerDelegate, and I'm pretty sure that if you try to implement this using the delegate, you're going to go through a lot of trouble to get this working right, when you could do it more easily and cleanly by using a subclass ofUINavigationController that overrides:

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated;
- (UIViewController *)popViewControllerAnimated:(BOOL)animated;
and if you plan to use them 
- (NSArray *)popToViewController:(UIViewController *)viewController animated:(BOOL)animated;
and
- (NSArray *)popToRootViewControllerAnimated:(BOOL)animated;

You will also need to store the view to be added to the transitioning view, in the navigation controller, as an instance variable. In the example I will call it viewForTransition.

an example of one of the overridden methods:

- (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated {
     // Submit an animation which adds the viewForTransitioning to the view about to be pushed off screen.
     // Upon completion, the animation will remove the viewForTransitioning from it's superview.
     // You also need to figure out the proper duration and delay and store them in constants or as instance variables.

     [UIView animateWithDuration:theDuration delay:theDelay options:UIViewAnimationOptionCurveLinear animations:^{
          [self.topViewController.view addSubview:self.viewForTransition];
     } completion:^{
          [self.viewForTransition removeFromSuperview];
     }];
     // after submitting the animation, call super.
     // if this makes the view appear for a few moments and then disappear before animating to the next view controller, you might try calling super after calling addSubview.
     // if that doesn't work you can try storing the old top view controller in an instance variable so that it can be accessed by the delegate when navigationController:willShowViewController:animated: is called.
     [super pushViewController:viewController animated:animated];
}

I'm not totally sure that this will do what you want. But it's worth a try.