Flutter get value from provider-CodePudding

I am using provider as state management. To use value between multiple files i create a provider like this

class globalProvider with ChangeNotifier, DiagnosticableTreeMixin {
  String uuID = "";

  String get _uuID => uuID;

  void changeuuID(id) {
    uuID = id;
    notifyListeners();
  }

}

I am updating value like this

   final uuidUpdate = Provider.of<globalProvider>(context, listen: false);
   uuidUpdate.changeuuID(user.uid);

Now on other page I need to print uuID value. I try to do like this

  print(Provider.of<globalProvider>(context).uuID);

But its showing error Tried to listen to a value exposed with provider, from outside of the widget tree.

main.dart

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();

  runApp(
    MultiProvider(
      providers: [
        ChangeNotifierProvider(create: (_) => globalProvider()),
      ],
      child: MaterialApp(
        debugShowCheckedModeBanner: false,
        home: LoginPage(),
      ),
    ),
  );
}

CodePudding user response：

you need to add your state up in your widgets tree like:

ChangeNotifierProvider(
        create: (context) => globalProvider (),
        builder: (context, _) {
    return theRestOfTheTreeWidgets();}
    )

CodePudding user response：

in your main.dart add ChangeNotifierProvider.value(value: GlobalProvider) in MultiProvider widget,

Make sure that your class starts with capital letter and let me know if arrow still exists.

CodePudding user response：

please use below code .. if its help you ..please upvote my answer and mark as accepted..if you find and problem please let me know and use this package

get_it: ^7.2.0

class GlobalProvider with ChangeNotifier, DiagnosticableTreeMixin {
  String _uuID = "";

  String get uuID => _uuID;

  void changeuuID(id) {
    _uuID = id;
    notifyListeners();
  }

}

in your main.dart .please must use Upper cast and paste the below code in main.dart

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
 await di.init();
  runApp(
    MultiProvider(
      providers: [
          ChangeNotifierProvider(create: (context) => di.sl<GlobalProvider >()),
      ],
      child: MaterialApp(
        debugShowCheckedModeBanner: false,
        home: LoginPage(),
      ),
    ),
  );
}

make a new dart file and paste this code

final sl = GetIt.instance;

Future<void> init() async {
    sl.registerFactory(() => GlobalProvider ());
}

and I use this init() function in main file already ..just import library