Flutter 应用程序有时卡在启动画面上

Question

当应用程序一段时间未使用时（例如多天）或有时当我恢复最近的应用程序时，应用程序会在启动屏幕上的 Android 和 iOS 处冻结，而不是在图标点击时打开应用程序。

它只是显示一个启动画面，应用程序是黑色的（因为我有深色主题）和一个应用程序图标，它会粘在那里。

我唯一的逻辑是初始化 Firebase 并检查用户是否登录。

这是 main.dart：

///Receive message when app is in background solution for on message
Future<void> backgroundHandler(RemoteMessage message) async {
  print('Handling a background message ${message.messageId}');
  print('Content of message: ' + message.toString());
}

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  configureInjections();
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );
  FirebaseMessaging.onBackgroundMessage(backgroundHandler);
  runApp(App());
}

class App extends StatelessWidget {
  @override
  Widget build(BuildContext context) => MultiBlocProvider(
        providers: [
          BlocProvider(create: (context) => getIt<SplashScreenCubit>()),
          BlocProvider(create: (context) => getIt<HomeCubit>()),
          BlocProvider(create: (context) => getIt<LogInCubit>()),
          BlocProvider(create: (context) => getIt<SettingsCubit>())
        ],
        child: OverlaySupport(
          child: MaterialApp(
            debugShowCheckedModeBanner: false,
            title: 'SAY',
            theme: appTheme,
            home: SplashScreenPage(),
          ),
        ),
      );
}

这是启动页面：

class SplashScreenPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) => getIt<SplashScreenCubit>()..isUserAuthenticated(),
      child: BlocConsumer<SplashScreenCubit, SplashScreenState>(
          listener: (context, state) {
            if (state is Authenticated) {
              PageNavigator.navigateAndRemoveHistory(context, HomePage());
            }
            if (state is Unauthenticated) {
              PageNavigator.navigateAndRemoveHistory(context, LogInPage());
            }
            if (state is SplashError) {
              PageNavigator.navigateAndRemoveHistory(context, LogInPage());
            }
          },
          builder: (context, state) => SplashScreenContent()),
    );
  }
}

class SplashScreenContent extends StatelessWidget {
  @override
  Widget build(BuildContext context) => Scaffold(
        body: Container(
          height: MediaQuery.of(context).size.height,
          width: MediaQuery.of(context).size.width,
          color: AppColors.primaryColor,
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              Expanded(
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                    Text('SAY', style: Theme.of(context).textTheme.headline1),
                    Text('Together we make it better!',
                        style: Theme.of(context)
                            .textTheme
                            .headline6!
                            .copyWith(color: AppColors.whiteColor),
                        textAlign: TextAlign.center),
                  ],
                ),
              ),
              Expanded(
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.end,
                  crossAxisAlignment: CrossAxisAlignment.end,
                  children: [Image.asset(SvgIcons.splashScreenLogo)],
                ),
              )
            ],
          ),
        ),
      );
}

这是肘：

@injectable
class SplashScreenCubit extends Cubit<SplashScreenState> {
  final IsUserAuthenticatedUseCase _isUserAuthenticatedUseCase;

  SplashScreenCubit(this._isUserAuthenticatedUseCase) : super(Initial());

  Future<void> isUserAuthenticated() async {
    print("Called isUserAuthenticated on the splash screen");
    try {
      var isUserAuthenticated = await _isUserAuthenticatedUseCase.execute(NoParams());
      return isUserAuthenticated ? emit(Authenticated()) : emit(Unauthenticated());
    } catch (e) {
      emit(Unauthenticated());
    }
  }
}

这是对用例和存储库的调用：

  @override
  Future<bool> isAuthenticated() {
    try {
      var currentUser = _firebaseAuth.currentUser;
      return Future.value(currentUser != null && currentUser.emailVerified);
    } catch (e) {
      return Future.value(false);
    }
  }

Answer 1

好的，在你的main.dart试试这个。 首先，我将使用StreamBuilder和Firebase方法userChanges来检查auth state ：

home: StreamBuilder(
          stream: FirebaseAuth.instance.userChanges(),
          builder: (context, snapshot) {
            if (snapshot.connectionState == ConnectionState.active) {
              if (snapshot.hasData) {
                return HomePage();
              } else if (snapshot.hasError) {
                return Center(
                  child: Text('${snapshot.error}'),
                );
              }
            }
            if (snapshot.connectionState == ConnectionState.waiting) {
              return Center(
                child: CircularProgressIndicator(),
              );
            }
            return LogInPage();
          },
        ),