GameCenter login alert

Question

In a game I am developing using GameCenter, I want to handle the following scenario:

1. the user starts up the game. He is shown the system alert that prompts him to

Answer 1

I am playing around with Game Center myself right now I have seen the very same behavior. There is nothing in the documentation saying anything about the dialog only showing up the first couple of times. In my case I would like a way to tell beforehand if the user is already logged into Game Center, so that I can behave appropriately. But now I can not know this before the dialog is shown to the user.

Since we are running in the sandbox during development this behavior might of course be something that behaves differently during production but this is not an easy thing to find out.