viewDidAppear: not firing under certain conditions?

Question

I have the following items in my app nib:

• the usual: file's owner, first responder window, delegate
• View Controller "a"
  • View "b"
    • UIScrollView "c"
    • some other stuff in "b"

In my AppDelegate applicationDidFinishLaunching, I do this:

1. [window makeKeyAndVisible]
2. [window addSubView:a.view];
3. create a view controller "d"
4. create a navigationController "e" with rootviewcontroller "d"
5. invoke [c addSubView:e.view]

Question/problem: when I do all of the above, viewDidAppear: is not firing for "d". (but viewDidLoad IS firing.) How do I find out why it is not firing, and fix it so that it would fire?

(Why I want to use viewDidAppear: the above involves some chained animations and viewDidAppear looks like a good place for a view controller to know when its view has been loaded and animated, so it can trigger subsequent animations.)

Answer 1

Usually when you're manually screwing with the view hierarchy you won't get -viewWillAppear:, -viewDidAppear, etc.; they're called by various SDK methods, like -pushViewController:animated:, -presentModalViewController:animated:, and by UITabBarController when a tab gets selected.

When you add a view to the hierarchy yourself, it may or may not be onscreen or going-to-be-onscreen; the -addSubview: method doesn't make any assumptions about your intentions. Just call 'em yourself as you add the view.