I have 3 viewControllers named firstController, secondController and thirdController. My logic is firstController.presentViewController(secondController), then secondController.presentViewController(thirdController), and the set a rootViewController by UIApplication.shareApplication().keywindow!.rootViewController = firstController...
But when I set firstController as the rootViewController, when presenting viewController from secondController to thirdController with thirdController.modalTransitionStyle = UIModalTransitionStyle.CrossDissolve, the firstController will show during the animate.
May I should not use the rootViewController like this?