Not updating the value of bool variable-CodePudding

Here you have the code from MyApp:

class MyApp extends StatefulWidget {
  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {

  bool isLoggedIn = false;



  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    comprobarEstado();
  }
  Future<void> comprobarEstado() async {

    final SharedPreferences prefs = await SharedPreferences.getInstance();
     isLoggedIn = ((prefs.getBool('logeado') == null) ? false : prefs.getBool('logeado'))!;
     print ("Estado ${isLoggedIn}");

  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        localizationsDelegates: context.localizationDelegates,
        supportedLocales: context.supportedLocales,
        locale: context.locale,
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home:  isLoggedIn ? MyHomePage() : LoginScreen());
  }
}

If the value of isLoggedIn is true, I want to launch MyHomePage, and if it is false I want to launch LoginPage.

The current value for isLoggedIn is true, but it always launch LoginPage.

I would like to know the proper way to get the value for isLoggedIn and to open the right page depending on its value.

CodePudding user response：

The comprobarEstado method is async and your widget will be built before the future is resolved and you have no code to trigger a rebuild once the value changes. An easy fix is to change your method to:

Future<void> comprobarEstado() async {

    final SharedPreferences prefs = await SharedPreferences.getInstance();
    setState(() {
     isLoggedIn = ((prefs.getBool('logeado') == null) ? false : prefs.getBool('logeado'))!;
    });
     
     print ("Estado ${isLoggedIn}");

  }

Calling setState is going to trigger the widget to rebuild.