使用go_router传递验证数据

Question

在我的项目中，我实现了管理状态的提供者方法，我想与GO Router软件包共享Auth Provister信息，以使用户登录

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MultiProvider(
        providers: [
          ChangeNotifierProvider(
            create: (ctx) => Auth(),
          ),
         ListenableProxyProvider<Auth, AppRouter>(
            update: (_, authObj, prevOrders) =>
               AppRouter(authObj)
          ),
}

和在我的Applouter类中，我有一个限制者可以获取auth Data：

class AppRouter with ChangeNotifier {
  final Auth authData;
  AppRouter(this.authData);
  final router = GoRouter(
    initialLocation: '/',
    routes: [

     
      GoRoute(
        name: root,
        path: '/',
        builder: (context, state) => TabsScreen(),
        // redirect: (state) => state.namedLocation(authScreen),
      ),
      GoRoute(
        name: mainScreen,
        path: '/main-screen',
        builder: (context, state) => HomeScreen(),
      ),
      GoRoute(
        name: authscreen,
        path: '/auth-screen',
        builder: (context, state) => AuthScreen(),
      ),

],

    redirect: (state) {
      final loginLoc = state.namedLocation(authScreen);
      final loggingIn = state.subloc == loginLoc;

  var loggedIn = authData.isLoggedIn;
 if (!loggedIn && !loggingIn) return loginLoc;
  if (loggedIn && (loggingIn)) return root;

      return null;
    },

但是我可以't访问我的班级中的authdata，我会收到此错误：

The instance member 'authData' can't be accessed in an initializer.
Try replacing the reference to the instance member with a different expression

Answer 1

本文帮助我解决了问题，还有有关使用go_router实施导航2.0的完整指南：

flutter导航器2.0：使用go_router

Answer 2

这是正常的。即使您在想：“当我将我的authdata分配给DART时，重定向也会发生。对于DART，您正在尝试在创建路​​由器的时刻使用Authdata的值，因此未分配它。例如，如果Authdata是一个静态字段，并且已经分配了，则可以执行此操作。

您可能可以通过阅读此书来实现您要实现的目标：
https://gorouter.dev/parameters

编辑：
这是我要做的代码段：

final router = GoRouter(
    initialLocation: '/',
    routes: [
      GoRoute(
        name: root,
        path: '/',
        builder: (context, state) => TabsScreen(),
      ),
      GoRoute(
        name: mainScreen,
        path: '/main-screen',
        builder: (context, state) => HomeScreen(),
      ),
      GoRoute(
        name: authscreen,
        path: '/auth-screen',
        builder: (context, state) => AuthScreen(),
      ),

    ],

    redirect: (state) {
      final Auth data=state.extra! as Auth;
      final loginLoc = state.namedLocation(authScreen);
      final loggingIn = state.subloc == loginLoc;

      var loggedIn = data.isLoggedIn;
      if (!loggedIn && !loggingIn) return loginLoc;
      if (loggedIn && loggingIn) return root;

      return null;
    },
);

注意：记住要始终通过这样的状态：

context.go('/route', extra:authData);