how to retrieve a value from shared preferences instantly? - FLUTTER

Question

I'm trying to show a page as an initial login, this is only displayed when my switch value is set to true. The switch value is stored with shared preferences but when I open the application it is not recovered, only after an application update is it actually recovered. how can i get it to be recovered instantly when i open my application?

below the code:

Future<bool> saveSwitchState(bool value) async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.setBool("switched", value);
    print('Switch Value saved $value');
    return prefs.setBool("switched", value);
  }

Future<bool> getSwitchState() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    SettingsPage.switched = prefs.getBool("switched")!;
    print(SettingsPage.switched);

    return SettingsPage.switched;
  }

on another page then the value that is actually recovered:

if(AuthPage.authenticated == false && SettingsPage.switched == true ) {
      yield ProfileNoAuth();
      return; }

Answer 1

you can use dependency injection follow these steps : get it package

create a Separate dart containing the following code file like this:

GetIt locator = GetIt.instance;
Future<void> setupLocator() async {
SharedPreferences sharedPreferences = await SharedPreferences.getInstance();
locator.registerLazySingleton<SharedPreferences>(() => sharedPreferences);  
}

call the setupLocator() method and wait for it in your main function

 void main() async {
    await setupLocator();
    runApp(App());
    }

access SharedPreferences Instance from anywhere like this: locator(); now the SharedPreferences Instance if available anywhere in your project please note that you dont have to wait for getting the Instance anymore, because you have only one Instance sharable across the application

    bool getSwitchState() {
    final prefs = locator<SharedPreferences>();
    SettingsPage.switched = prefs.getBool("switched")!;
    print(SettingsPage.switched);

    return SettingsPage.switched;
   }