SharedPreferences not working on real device FLUTTER

问题

I used SharedPreferences to make remember username and password to log in next time without asking a password. It was working well when I debug using my real device with USB cable. But it's not working in my device when I build APK and install it. I don't know what I'm missing.

I save data in login page like this`

Future<Null> loginUser(isLogin, name, fac, year, gender) async {
final SharedPreferences prefs = await SharedPreferences.getInstance();
prefs.setString('Name', name);
prefs.setString('IsLogin', isLogin);
prefs.setString('Faculty', fac);
prefs.setString('Year', year);
prefs.setString('Gender', gender);
prefs.setString('Email', email);

print(prefs.getString('Faculty'));

}

I used this code in main page....

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
  Widget build(BuildContext context) {
    return NewMain();
  }
}

class NewMain extends StatefulWidget {
  @override
  _NewMainState createState() => _NewMainState();
}

class _NewMainState extends State<NewMain> {
  var name, fac, year, gender, email;
  var goToLogin = true;
  @override
  void initState() {
    // TODO: implement initState
    checkRem();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    if (goToLogin)
      return MaterialApp(
        home: Login(),
      );
    else
      return MaterialApp(
        home: MainClass(name, fac, year, gender, email),
      );
  }

  void checkRem() async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    if (prefs.getString('IsLogin') == 'Yes') {
      goToLogin = false;
      fac = prefs.getString('Faculty');
      name = prefs.getString('Name');
      gender = prefs.getString('Gender');
      year = prefs.getString('Year');
      email = prefs.getString('Email');
    }
  }
}

It will move to MainClass if goToLogin is false. It's working perfectly in debug. It's not working on the built apk app.

Solved

It was problem with my IDE. Updated and fixed

回答1:

Problem is u calling checkRem() which is async in initState() so build method getting called before complete execution of checkRem().

Soln: wrap it with futureBuilder() or calling setState() after complete execution of method

来源：https://stackoverflow.com/questions/60808628/sharedpreferences-not-working-on-real-device-flutter

标签

Flutter

sharedpreferences