How does [UIAlertView show] work?

I want to do something similar to UIAlertView, ie - without reference to any UIView or UIViewController, present a UIViewController on top of all windows using presentModalViewController.

Looking at the documentation I can't find a way in which this is possible!

In OS4, there is something like this:

UIWindow *window = [UIApplication sharedApplication].keyWindow
UIViewController *rootViewController = window.rootViewController

...but this is not possible in OS3.

Does anyone know how to achieve the same effect in OS3?

Thanks!

OK - so I solved this with a myriad of delegate callbacks to the ViewController itself! Although it's the proper way to achieve this, it did seem kind-of odd that's it's not possible at any st开发者_开发知识库age in execution get a handle to the top View Controller for alerts (etc).

If anyone knows how to achieve this, I'd be still really interested!

UIAlertView creates its own UIWindow above your application's main window, makeKeyAndVisible-s it, and animates in its own views in that window.