popToRootViewControllerAnimated question

I've got next question - why my app dont waiting when i call

[navController popToRootViewControllerAnimated:NO];
... set开发者_开发知识库 new viewcontrollers here

I want:

1/ Kill all viewcontrollers by call popToRootViewControllerAnimated - with NO parameter - then i think i can immediately set new view controllers

2/ set new view controllers

But in my logs i see next:

call poptorootview controller

code after poptorootview

dealloc of views and controller (because i call poptorootview)

Why ? How can I detect that all views is killed and navigation controller is poping to root ? Thanks,

A popped view controller will eventually be released (unless another object retains it), but the reference does not specify exactly when and how it is released. I wouldn't be surprised if it is not immediately released; the UIKit objects may use the view controller for the transition animation. It may be autoreleased not released, which may explain your logs. Also, I wouldn't be surprised inside UINavigationController multiple objects are retaining view controllers in the stack at the same time. Concisely speaking, there is no documented behavior about releasing popped view controllers. All we can be sure of is that it will be released at some point, as otherwise it will lead a memory leak.

Therefore you don't know when the view controllers are actually deallocated. Even if you find out it is subject to change without a notice. However, you can be sure when the view disappeared, using UINavigationController's delegate methods.