Flutter 自动路由 : How to set initial route programmatically?

Question

我有一个带主屏幕的登录屏幕。用户登录后，它将用户重定向到主屏幕。但是，我有一个 bloc 检查用户之前是否经过身份验证，如果是，它会将用户直接重定向到主屏幕。

但是，它并没有按预期工作。 “isLoggedIn” bool 值发生变化，但 UI 没有反应。如何解决？

这是代码

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
import 'package:harnasik/core/router/app_router.gr.dart';
import 'package:harnasik/core/style/custom_colors.dart';
import 'package:harnasik/features/authorization/presentation/blocs/log_in/log_in_bloc.dart';
import 'package:harnasik/generated/l10n.dart';
import 'package:harnasik/injection_container.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await InjectionContainer().init();
  runApp(const HarnasikApp());
}

class HarnasikApp extends StatefulWidget {
  const HarnasikApp({Key? key}) : super(key: key);

  @override
  _HarnasikAppState createState() => _HarnasikAppState();
}

class _HarnasikAppState extends State<HarnasikApp> {
  late final LogInBloc logInBloc;
  late bool isLoggedIn;
  final AppRouter _appRouter = sl();

  @override
  void initState() {
    logInBloc = sl();
    super.initState();
    isLoggedIn = false;
    logInBloc..add(CheckIfUserLoggedInEvent());
  }

  @override
  void dispose() {
    logInBloc.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return BlocListener(
      bloc: logInBloc,
      listener: (context, state) {
        if (state is LoggedInState) {
          isLoggedIn = true;
        } else if (state is LogInErrorState) {
          print('Error'); // For tests only
        }
      },
      child: MaterialApp.router(
        debugShowCheckedModeBanner: false,
        theme: ThemeData(
          primaryColor: CustomColors.blue,
          fontFamily: 'Lato',
        ),
        routerDelegate: _appRouter.delegate(
          initialRoutes: [
            if (!isLoggedIn) const LogInScreen() else const HomeScreen(),
          ],
        ),
        routeInformationParser: _appRouter.defaultRouteParser(),
        localizationsDelegates: const [
          S.delegate,
          GlobalWidgetsLocalizations.delegate,
          GlobalMaterialLocalizations.delegate,
          GlobalCupertinoLocalizations.delegate
        ],
        supportedLocales: S.delegate.supportedLocales,
      ),
    );
  }
}

Answer 1

我使用这样的 auto_route 守卫解决了同样的问题:

/// An auto_route guard object that routes the user to our landing page if
/// signed in and to the home page if not signed in 
class GetInitialRoute extends AutoRouteGuard {

  @override
  void onNavigation(NavigationResolver resolver, StackRouter router) {

    // Here we check if the user is logged in using FirebaseAuth (not currentUser --> 
    // not logged in)
    if (FirebaseAuth.instance.currentUser == null) {
      // if we do not have a user yet, we resume navigation to the sign in page 
      // with path: '/'
      resolver.next(true);
    } else {
      // if we already have a logged in user, we push them to our home page
      router.push(const HomeRoute());
    }
  }
}

请阅读这篇关于 auto_route 中身份验证的文章 LINK和这篇关于 route_guards 的文章 LINK了解更多。这些文章还解释了如何将守卫应用到您的路线。