Flutter应用程序有时会在启动屏幕上卡住

Question

在Android和iOS系统中，如果有一段时间(比如好几天)不使用应用程序，或者当我恢复最近的应用程序，而不是通过点击图标打开应用程序时，应用程序会在启动画面上冻结。

它只是显示一个闪屏，应用程序是黑色的(因为我有黑色的主题)和一个应用程序图标，它停留在那里。

我唯一的逻辑是初始化Firebase并检查用户是否登录。

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(),
),
),
);
}

Splash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cubit:

@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());
}
}
}

下面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，在您的main.dart中尝试此操作。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();
},
),