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Getting to a specific view manager in the navigation stack

I came across a piece of code that needs to be placed in a specific view manager in the navigation stack, as shown below.

for (UIViewController* viewController in self.navigationController.viewControllers) {
    if ([viewController isKindOfClass:[MyGroupViewController class]] ) {
        MyGroupViewController *groupViewController = (MyGroupViewController*)viewController;
        [self.navigationController popToViewController:groupViewController animated:YES];
    }
}

The goal is pop to MyGroupViewController. But I do not understand this line of code.

MyGroupViewController *groupViewController = (MyGroupViewController*)viewController;

What's going on here? I do not think that a new instance of MyGroupViewController is being created here.

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4 answers
//This for loop iterates through all the view controllers in navigation stack.   
for (UIViewController* viewController in self.navigationController.viewControllers) {

    //This if condition checks whether the viewController class is MyGroupViewController 
    // if true that means its the MyGroupViewController (which has been pushed at some point)
    if ([viewController isKindOfClass:[MyGroupViewController class]] ) {

        // Here viewController is a reference of UIViewController base class of MyGroupViewController 
        // but viewController holds MyGroupViewController  object so we can type cast it here
        MyGroupViewController *groupViewController = (MyGroupViewController*)viewController;
        [self.navigationController popToViewController:groupViewController animated:YES];
    }
}

Also you can do it

if ([viewController isKindOfClass:[MyGroupViewController class]] ) {
            [self.navigationController popToViewController:viewController  animated:YES];
 }

Quick code

//Itrate through all the view controllers in navigation stack
for vc in self.navigationController!.viewControllers {
  // Check if the view controller is of MyGroupViewController type
  if let myGropupVC = vc as? MyGroupViewController {
    self.navigationController?.popToViewController(myGropupVC, animated: true)
  }
}
+21
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. ( UIViewController), UIViewController. , , , MyGroupViewController. , , , , .

, :

(UIViewController* viewController in self.navigationController.viewControllers) {
    if ([viewController isKindOfClass:[MyGroupViewController class]] ) {
        [self.navigationController popToViewController:viewController animated:YES];
    }
}

: , , .

+2
for (int m=0; m<[self.navigationController.viewControllers count]; m++)   
{  

        if([[self.navigationController.viewControllers objectAtIndex:m] isKindOfClass:[MyGroupViewController class]])  
            { 

                MyGroupViewController * groupViewController = [self.navigationController.viewControllers    objectAtIndex:m];  
                [self.navigationController popToViewController:groupViewController animated:YES];   
             }   
}
+1
- (void) RetunToSpecificViewController{

    for (UIViewController *controller in self.navigationController.viewControllers) {
        if ([controller isKindOfClass:[AnOldViewController class]]) { 
        //Do not forget to import AnOldViewController.h

            [self.navigationController popToViewController:controller
                                              animated:YES];
            break;
        }
    }

Swift

func RetunToSpecificViewController()
{
    let viewControllers: [UIViewController] =  self.navigationController!.viewControllers as [UIViewController]
  self.navigationController!.popToViewController(viewControllers[viewControllers.count
        - 5], animated: true)
}

We have the best tutorial on this, you can check https://appengineer.in/2014/03/13/pop-to-specific-view-controller-in-ios/

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