Question

I am just looking for a sanity check here.

I have a screen that the user passes through on the way into the main application. That screen can be navigated back to from almost anywhere in the system.

As it stands I am just presenting ViewControllers without using a NavController to manage them (it does not seem applicable for most of my app, since screens are not necessarily sequential or related to one another).

My question is, if I have presented VC1, then navigate to other screens, and finally want to present VC1 again, I am doing something like:

[self presentViewController:[self.storyboard instantiateViewControllerWithIdentifier:@"VC1"] animated:YES completion:nil];

Is this bad form? Am I leaking memory by creating a bunch of VC1 instances or is there some magic that uses the previously created one?

If it is bad form, how do I get back to the original VC1 to reuse it?

Thanks for any input.

Answer 1

I think you pegged it: It’s not a great idea to have multiple instances of the same view controller in memory at the same time. Every time you instantiate a new view controller and present it modally, you’ll consume more memory.

The most elegant solution is the iOS 6 unwind segue. But most of us would be unwilling to give up on iOS 5 support quite yet.

If you need to support iOS 5, you could contemplate using navigation controller, but hide the navigation bar if you don’t like it in your user interface. Then replace modal segues with push segues and now you can do popToRootViewController whenever you want to return to the main view controller.