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!

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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!

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