Question

I have found a strange behaviour when trying to push a viewcontroller onto the stack. The following works fine:

[self.navigationController pushViewController:myViewController animated:YES];

but if I change it to animated:NO it no longer works, doesn’t seem to push at all. I was performing this in a viewWillAppear but I have also tried it in viewDidAppear but with no luck.

Any ideas what could be causing this?

Thanks

Answer 1

The problem is most probably not the call itself, but the placement of the call. Try putting the same action on a UIButton and it should 100% work. I’ve noticed that putting view controller manipulation routines like presentModal… and pushViewController… don’t sometimes work in the viewWill* viewDid* methods. Or try making the calls from those functions with a performSelector:withObject:afterDelay after a short delay and see if that works.

Edit: there are a couple of ways of doing what you want to do. You can directly modify the navigation stack of a navigation controller, so when you are in view N+1, you can replace view N on the stack (by building a new navigation stack array and setting it in to the navigation controller), then pop, and you’ll get the effect of “popping back to a different view controller”. You can also issue multiple pops and pushes from the view controller you want to leave, but you have to be careful:

// pop back 2 controllers on the stack to the setup screen
//

// locally store the navigation controller since
// self.navigationController will be nil once we are popped
//
UINavigationController *navController = self.navigationController;

// retain ourselves so that the controller will still exist once it's popped off
//
[[self retain] autorelease];

// Pop back 2 controllers to the setup screen
//
[navController popViewControllerAnimated:NO];
[navController popViewControllerAnimated:YES];