Flutter 最佳实践在屏幕之间共享数据

Question

I'm new in flutter and I read lot of documentations on multiple subjets. One of them is sharing data between screens. I found a lot of solutions and as I'm creating a base project with lot of features, I want to know which one is the best

Solution 1: In constructor

Basically, when we navigate, we send the data through the next constructor widget.

Solution 2: In session

Creates a singleton which can be access from everywhere in the application and each time you need to send data, you add it in the session and the next widget can retrieve it.

Solution 3: In blocs

I read this solution which looks good:

I made a BLoC container class where I've instantiated the BLoCs of the two screen. Then here I set the reference from the BLoC A to a stream of the BLoC B where I want to send the data. The BLoCs are still decoupled cause they don't know anything about each other, the BLoC A doesn't get passed through the constructor on the BLoC B and vice versa, but it just knows that it will receive some data on one of its streams.

UPDATED:

Solution 4: Inherited widget

With a static function like:

static InheritedDataProvider of(BuildContext context) => context.inheritFromWidgetOfExactType(InheritedDataProvider);
}

So you can access to the data initialized in the parent with something like: final data = InheritedDataProvider.of(context).data;

Maybe there are others solutions and I'll be glad to know them. Thanks

Answer 1

What I use:

1. Call next screen with Navigator.pushNamed(ctx, '/foo', arguments: bar) . Only include arguments if needed (eg for "update detail" screen).
2. Centralize all possible routes in the widget that contains MaterialApp .
3. Pass a clone of the passed argument to the next screen (immutable data).

In code:

  ...
  MaterialApp(
    onGenerateRoute: (s) => MaterialPageRoute(builder: (ctx) => _route(s), settings: s),
  )
  ...

  Widget _route(RouteSettings route) {
    switch (route.name) {
      case '/signup':
        return SignupRoute();
      case '/vendor':
        return VendorRoute((route.arguments as Vendor)?.data?.clone());
      default:
        throw ('No match for ${route.name}');
    }
  }

Answer 2

The best way is passing a parameter to the constructor

Navigator.push(
                context,
                PageTransition(
                    type: PageTransitionType.fade,
                    child: LoginPage(
                      userModel: model,
                    )));

then:

class LoginPage extends StatefulWidget {
  LoginPage({this.userModel});
  User userModel;
  @override
  _LoginPageState createState() => _LoginPageState(userModel: userModel);
  }  

 class _LoginPageState extends State with TickerProviderStateMixin {
  User userModel;
  _LoginPageState({this.userModel}); 

   }
}