Controlling State from outside of a StatefulWidget

Question

I\'m trying to understand the best practice for controlling a StatefulWidget\'s state outside of that Widgets State.

I have the following interface defined.

<

Answer 1

There is another common used approach to have access to State's properties/methods:

class StartupPage extends StatefulWidget {
  StartupPage({Key key}) : super(key: key);

  @override
  StartupPageState createState() => StartupPageState();
}

// Make class public!
class StartupPageState extends State {
  int someStateProperty;

  void someStateMethod() {}
}

// Somewhere where inside class where `StartupPage` will be used
final startupPageKey = GlobalKey();

// Somewhere where the `StartupPage` will be opened
final startupPage = StartupPage(key: startupPageKey);
Navigator.push(context, MaterialPageRoute(builder: (_) => startupPage);

// Somewhere where you need have access to state
startupPageKey.currentState.someStateProperty = 1;
startupPageKey.currentState.someStateMethod();