How to detect which child view controller was popped up in iOS? - ios

Question

I have view controller say A i am going from A to B.Then on B by pressing back button i am coming to A.Now i want to know from which view controller i am coming back.Please tell me how can i do this.I know i can do it by using viewWillAppear method but don't want to use this.
Please tell which is the best way of doing it?
-(void)viewWillAppear:(BOOL)animated
{
NSLog(#"view will appear called");
}

Answer 1

You have been push to B-VC from A-VC right.You can come back by popping.
self.navigationController!.popViewControllerAnimated(true)--Write this code in B-VC
VC-ViewController.

Answer 2

- (id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
animationControllerForOperation:(UINavigationControllerOperation)operation
fromViewController:(UIViewController *)fromVC
toViewController:(UIViewController *)toVC
{
NSLog(#"from VC class %#", [fromVC class]);
if ([fromVC isKindOfClass:[ControllerYouJustPopped class]])
{
NSLog(#"Returning from popped controller");
}
return nil;
}
This really saved me .

Answer 3

you can pass id of controller before pop A.h #property NSInteger childVC; A.m
-(void)viewWillAppear:(BOOL)animated
{
if (_childVC == 3){
//todo
}
}
B.m
-(void) viewWillDisappear:(BOOL)animated {
A *parent = (A *)self.navigationController.viewControllers[self.navigationController.viewControllers.count - 2];
parent.childVC = 3;
[super viewWillDisappear:animated];
}
I do not see other ways

Answer 4

You could use a navigation controller delegate and implement the following UINavigationControllerDelegate method:
- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
UIViewController *fromViewController = [navigationController.transitionCoordinator viewControllerForKey:UITransitionContextFromViewControllerKey];
NSLog(#"%#", fromViewController.title);
}