Issue with popViewController and pushController

Question

I'm facing issue with redirecting the viewControllers using pop/pushViewControllers. I've three view controller like below image -

Control Flow

In my 3rd view i've some ToggleButton based on that toggleButton the data which is in 2nd View will change. After, changing something on 3rd view and press Done button in my 3rd View i just started my 2nd ViewController using pushViewController And, the changes are occured successfully.

But, what was the issue is, when i try to press the back button on my 2nd view page its redirecting me again to 3rd viewController (Because of pushViewController)

I try to start my 2nd view using popViewController but, its giving exception.

Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Tried to pop to a view controller that doesn't exist.

I've used below code -

SecondViewController *second = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
second.array = resultArray;
second.indexValue = ind;
[self.navigationController popToViewController:second animated:YES];

How do i solve this issue? Any idea?

jithinroy · Accepted Answer · 2012-10-29T09:59:38.230

1

From 3rd viewcontroller you just need to call this method to pop to 2nd viewcontroller :

[self.navigationController popViewControllerAnimated:YES];

EDIT :

For notifying the second vc for data change you can use delegate. Follow this :

On ThirdViewController.h

@protocol DataChangeProtocol;
@interface ThirdViewController : UIViewController

@property(nonatomic,assign) id<DataChangeProtocol> delegate;

@end


@protocol DataChangeProtocol

- (void)thirdViewcontroller:(ThirdViewController*)vc dataChangedto:(NSDictionary *)changedData;

@end

And before pushing the thridVC from secondVC assign secondVC as the delegate of thirdVC :

ThirdViewController *thirdVC = [[ThirdViewController alloc]init..];
thirdVC.delegate = self;
[self.navigationController pushViewController:thirdVC animated:YES];

and in SecondViewController.m

- (void)thirdViewcontroller:(ThirdViewController*)vc dataChangedto:(NSDictionary *)changedData {
 // Change your values in the UI using the passed value from changedData.

}

edited Oct 29 '12 at 09:59

answered Oct 29 '12 at 09:40

jithinroy

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Its fine. Then, how will i represent the changes whatever i've done in my 3rd View to 2nd viewController? – Praveenkumar Oct 29 '12 at 09:46
use delegate to pass the changes to second viewcontroller to thridviewcontroller. or even better keep the changes in a central datamodel where the second viewcontroller can access it when it appears. – jithinroy Oct 29 '12 at 09:47
How can i do this? Is there any example for this functionality? – Praveenkumar Oct 29 '12 at 09:49
have added a few code as edit in the answer. hope this will help – jithinroy Oct 29 '12 at 10:00
Will try this and let you know. – Praveenkumar Oct 29 '12 at 10:00

score 1 · Answer 2 · edited Oct 29 '12 at 10:02

1

If you want to go to your current previous view controller then you have to do this:

[self.navigationController popViewControllerAnimated:YES];

edited Oct 29 '12 at 10:02

Emil

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answered Oct 29 '12 at 09:42

amit soni

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Its fine. Then, how will i represent the changes whatever i've done in my 3rd View to 2nd viewController? – Praveenkumar Oct 29 '12 at 09:46

score 1 · Answer 3 · answered Oct 29 '12 at 09:43

You create our viewcontroller:

SecondViewController *second = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];

and then you want to pop it from your stack but this controller is not in the stack, bacause you create it in the third viewController.

score 1 · Answer 4 · answered Oct 29 '12 at 09:58

    //it used in first class
     SecondViewController *second = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil];
second.array = resultArray;
second.indexValue = ind;
    [self.navigationController pushViewController:second animated:YES];
    //it move to second class

    //it used in second class
    [self.navigationController popViewControllerAnimated:YES];
    //it move to firsr class

Issue with popViewController and pushController

4 Answers4