Using SharedPreferences to set login state and retrieving it at App launch - Flutter

Question

I have an flutter app in which I have to check the login status when the app is launched and call the relevant screen accordingly.

The code used to launch the app:

Answer 1

You can use FutureBuilder to solve this problem.

@override
Widget build(BuildContext context) {
 new FutureBuilder<String>(
    future: getLoginState(),
    builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
      switch (snapshot.connectionState) {
        case ConnectionState.active:
        case ConnectionState.waiting:
          return new Text('Loading...');
        case ConnectionState.done:
          if (snapshot.hasData) {
            loginState = snapshot.data;
            if(loginState) {
             return Container(child: Text('Logged In'));
            }
            else {
             return Container(child: Text('Not Logged In));
            }
          } else {
           return  Container(child: Text('Error..));
          }
      }
    },
  )
 }

Note: we don't need isLoggedIn state variable.