Return to the first index of UINavigationController?

I'm doing an application which uses a UINavigationController and I'm switching to other UIViewControllers as follows:

if(self.myViewController == nil){
    MyViewController *aViewController = [[MyViewController alloc] initWithNibName:@"MyViewController" bundle:nil];
    self.myViewController = aViewController;
    [aViewController release];
}

AppDelegate *delegate = [[UIApplication sharedApplication] delegate];
[delegate.myNavController pushViewController:myViewController animated:YES];

I imagine this is creating a pile of UIViewControllers into the UINavigationController, maybe an array of inde开发者_运维技巧xs? I would like to know how to turn back without having to be back one by one.

For example, I'm sailing through a few screens and with a button I would like to return at the first index of navigation. I would also like know how to modify indexes, view, erase and anything pertaining to this issue.

Sorry if I have not explained well.

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You've asked two questions.

The first is, how do I get back to my first view controller. As @Thomas Clayson and @ender have answered, you want the popToRootViewControllerAnimated: method of your navigationcontroller object for that.

The second is how to move to a particular index in the view controller stack. The answer to that is, you can set the array of viewControllers explicitly. So you can pull out the current listing of view controllers, modify it, and set it back into the navigationController stack. It'll reset the stack and animate you moving to the top item in the stack.

Thusly:

NSMutableArray *controllers = self.navigationController.viewControllers;
[controllers removeObjectAtIndex:[controllers count] - 1]; //or whatever
[self.navigationController setViewControllers:controllers animated:YES];

---

NSArray *viewControllers = [[self navigationController] viewControllers];
    for (int i = 0; i < [viewContrlls count]; i++){
        id obj = [viewControllers objectAtIndex:i];
        if ([obj isKindOfClass:[yourViewControllername class]]){
            [[self navigationController] popToViewController:obj animated:YES];
            return;
        }
    }

Using this you can come back to any specified viewController.

---

[self.navigationController popToRootViewControllerAnimated:YES];

Will take you back to the very first view controller (root view controller).

Hope this helps

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Use this

NSArray *viewContrlls=[[NSArray alloc] initWithArray:[[self navigationController] viewControllers]];
    id obj=[viewContrlls objectAtIndex:1];
    [[self navigationController] popToViewController:obj animated:YES];
    [viewContrlls release];

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You should use popToRootViewControllerAnimated: From UINavigationController class reference:

Pops all the view controllers on the stack except the root view controller and updates the display.

---

You can return to the first view with

[self.navigationController popToRootViewControllerAnimated:YES];

That being said, you can also remove a particular view controller, or navigate to a specific index in your view controller if you look at the example.

NSMutableArray *allViewControllers = [NSMutableArray arrayWithArray:navigationController.viewControllers];
// You can now manipulate this array with the methods used for NSMutableArray to find out / perform actions on the navigation stack   

[allViewControllers removeObjectIdenticalTo: removedViewController];
// You can remove a specific view controller with this. 

navigationController.viewControllers = allViewControllers;