How can I pop a view from a UINavigationController and replace it with another in one operation?

Question

I have an application where I need to remove one view from the stack of a UINavigationController and replace it with another. The situation is that the first view creates an

Answer 1

From experience, you're going to have to fiddle with the UINavigationController's viewControllers property directly. Something like this should work:

MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo];

[[self retain] autorelease];
NSMutableArray *controllers = [[self.navigationController.viewControllers mutableCopy] autorelease];
[controllers removeLastObject];
self.navigationController.viewControllers = controllers;
[self.navigationController pushViewController:mevc animated: YES];

Note: I changed the retain/release to a retain/autorelease as that's just generally more robust - if an exception occurs between the retain/release you'll leak self, but autorelease takes care of that.

Answer 2

After much effort (and tweaking the code from Kevin), I finally figured out how to do this in the view controller that is being popped from the stack. The problem that I was having was that self.navigationController was returning nil after I removed the last object from the controllers array. I think it was due to this line in the documentation for UIViewController on the instance method navigationController "Only returns a navigation controller if the view controller is in its stack."

I think that once the current view controller is removed from the stack, its navigationController method will return nil.

Here is the adjusted code that works:

UINavigationController *navController = self.navigationController;
MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo];

NSMutableArray *controllers = [[self.navigationController.viewControllers mutableCopy] autorelease];
[controllers removeLastObject];
navController.viewControllers = controllers;
[navController pushViewController:mevc animated: YES];

Answer 3

I use this solution to keep the animation.

[self.navigationController pushViewController:controller animated:YES];
NSMutableArray *newControllers = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];
[newControllers removeObject:newControllers[newControllers.count - 2]];
[self.navigationController setViewControllers:newControllers];

Answer 4

Thanks, this was exactly what I needed. I also put this in an animation to get the page curl:

        MyEditViewController *mevc = [[MYEditViewController alloc] initWithGizmo: gizmo];

    UINavigationController *navController = self.navigationController;      
    [[self retain] autorelease];

    [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration: 0.7];
    [UIView setAnimationTransition:<#UIViewAnimationTransitionCurlDown#> forView:navController.view cache:NO];

    [navController popViewControllerAnimated:NO];
    [navController pushViewController:mevc animated:NO];

    [UIView commitAnimations];

0.6 duration is fast, good for 3GS and newer, 0.8 is still a bit too fast for 3G..

Johan

Answer 5

NSMutableArray *controllers = [self.navigationController.viewControllers mutableCopy];
    for(int i=0;i<controllers.count;i++){
       [controllers removeLastObject];
    }
 self.navigationController.viewControllers = controllers;

Answer 6

For monotouch / xamarin IOS:

inside UISplitViewController class;

UINavigationController mainNav = this._navController; 
//List<UIViewController> controllers = mainNav.ViewControllers.ToList();
mainNav.ViewControllers = new UIViewController[] { }; 
mainNav.PushViewController(detail, true);//to have the animation