If I logged in, go to the main page without log in again.
like this
FirebaseAuth _auth = FirebaseAuth.instance;
User firebaseuser = _auth.currentUser;
if (firebaseuser == null) {
return runApp(MaterialApp(home: login()));
} else {
return runApp(MaterialApp(home: MainPage()));
}
however currentUser description says
You should not use this getter to determine the users current state, instead use [authStateChanges], [idTokenChanges] or [userChanges] to subscribe to updates.
So I decided to use idTokenChanges.
because it says
Notifies about changes to the user's sign-in state (such as sign-in or sign-out) and also token refresh events.
And I made it like this
Stream<User> loginstate = await FirebaseAuth.instance.idTokenChanges();
But i don't know how to use it.