CODEWITHSUNDEEP
iosobjective-cuinavigationcontroller
Allan Jiang
Allan Jiang

Reputation: 11331

UINavigationController pushViewController lifecycle

I have a two ViewControllers A and B, in between I use UINavigationController's pushViewController function to navigate, for example when press button on A, it navigates to B by executing:

[self.navigationController pushViewController:[[BViewController alloc] init] animated:YES];

When press button on B, it navigates to A by the same way.

I think every time I navigate in this way, I am creating a new instance of a view controller without deleting the old one. For example, if I navigate A -> B -> A, there will be two A controllers.

How can I better manage the memory in this case? Is there a recommended pattern to reuse generated view controllers (like singleton view controller?), or how should I properly release the view controller which is not in use?

Thank you

Upvotes: 1

Views: 688

Answers (1)

dichen
dichen

Reputation: 1633

Usually, if you navigate between A and B, the workflow should be like:

Push, A -> B,

[self.navigationController pushViewController:[[BViewController alloc] init] animated:YES];

Then Pop, A <- B,

[self.navigationController popViewControllerAnimated:YES];

So that A is the same instance.

Upvotes: 2

Related Questions