在 iOS 模拟器上只显示黑屏的 Flutter App

Question

我已经编写了一个使用 Bloc 模式和 GetIt 包的 Flutter 应用程序。奇怪的是，该应用程序在 Android 设备上运行良好，但在 iOS 模拟器上，它只显示黑屏...

这里是我的代码：

main.dart

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );

  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
  AppInitializer.init();

  runApp(App());
}

app_initializer.dart

import 'package:authentication_repository/authentication_repository.dart';
import 'package:get_it/get_it.dart';
import 'package:techniciens/blocs/blocs.dart';
import 'package:user_repository/user_repository.dart';

class AppInitializer {
  static final getIt = GetIt.instance;

  static void init() {
    _registerSingletons();
    _registerBlocSingletons();
  }

  static void _registerSingletons() {
    getIt.registerSingleton(AuthenticationRepository()..user.first);
    getIt.registerLazySingleton<UserRepository>(() => UserRepository());
  }

  static void _registerBlocSingletons() {
    getIt.registerLazySingleton<AuthenticationBloc>(() => AuthenticationBloc(
        authenticationRepository:
            GetIt.instance.get<AuthenticationRepository>()));

    getIt.registerLazySingleton<SettingsFormCubit>(() => SettingsFormCubit());
    getIt.registerLazySingleton<UserInfoCubit>(() => UserInfoCubit());
  }
}

app.dart

import 'package:authentication_repository/authentication_repository.dart';
import 'package:dynamic_color/dynamic_color.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:overlay_support/overlay_support.dart';
import 'package:techniciens/blocs/blocs.dart';
import 'package:techniciens/core/constants/constants.dart';
import 'package:techniciens/screens/screens.dart';
import 'package:get_it/get_it.dart';
import 'package:user_repository/user_repository.dart';

import 'core/theme/app_theme.dart';

class App extends StatelessWidget {
  final AuthenticationRepository _authenticationRepository =
      GetIt.instance.get<AuthenticationRepository>();
  final UserRepository _userRepository = GetIt.instance.get<UserRepository>();
  final AuthenticationBloc _authenticationBloc =
      GetIt.instance.get<AuthenticationBloc>();

  App({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MultiRepositoryProvider(
      providers: [
        RepositoryProvider.value(value: _authenticationRepository),
        RepositoryProvider.value(value: _userRepository),
      ],
      child: BlocProvider<AuthenticationBloc>.value(
        value: _authenticationBloc,
        child: const AppView(),
      ),
    );
  }
}

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

  @override
  State<AppView> createState() => _AppViewState();
}

class _AppViewState extends State<AppView> {
  final _navigatorKey = GlobalKey<NavigatorState>();

  NavigatorState get _navigator => _navigatorKey.currentState!;

  @override
  Widget build(BuildContext context) {
    return DynamicColorBuilder(
      builder: (ColorScheme? lightColorScheme, ColorScheme? darkColorScheme) {
        return OverlaySupport.global(
          child: MaterialApp(
            title: kLoginAppbarTitle,
            theme: AppTheme.lightTheme(lightColorScheme),
            darkTheme: AppTheme.darkTheme(darkColorScheme),
            themeMode: ThemeMode.system,
            debugShowCheckedModeBanner: false,
            navigatorKey: _navigatorKey,
            builder: (context, child) {
              return BlocListener<AuthenticationBloc, AuthenticationState>(
                listener: (_, state) {
                  switch (state.authStatus) {
                    case AuthenticationStatus.unauthenticated:
                      _navigator.pushAndRemoveUntil<void>(
                          LoginPage.route(), (route) => false);
                      break;
                    case AuthenticationStatus.authenticated:
                      _navigator.pushAndRemoveUntil<void>(
                          HomePage.route(), (route) => false);
                      break;
                    default:
                      break;
                  }
                },
                child: child,
              );
            },
            onGenerateRoute: (_) => SplashPage.route(),
          ),
        );
      },
    );
  }
}

splash_page.dart

import 'package:flutter/material.dart';

class SplashPage extends StatelessWidget {
  static Route<void> route() {
    return MaterialPageRoute<void>(builder: (_) => const SplashPage());
  }

  const SplashPage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const Scaffold(
      body: Center(
        child: CircularProgressIndicator.adaptive(strokeWidth: 5),
      ),
    );
  }
}

正如我在 Flutter Inspector 和一些

print

命令中看到的那样，应用程序正常运行，直到

BlocListener

落在

onGenerateRoute

.

它给了我这个

Launching lib/main.dart on iPhone 14 Pro in debug mode...
Running Xcode build...
Xcode build done.                                           13,8s
GrMtlCommandBuffer: WARNING: Creating MTLCommandBuffer while in background.
GrMtlCommandBuffer: WARNING: Creating MTLCommandBuffer while in background.
Debug service listening on ws://127.0.0.1:52638/_tIC8TChUyE=/ws
Syncing files to device iPhone 14 Pro...
flutter: dynamic_color: Dynamic color not detected on this device.

我已经删除了 iOS 模拟器上的所有数据，它没有提供任何东西......

在 Android 模拟器上，代码运行得非常好，但在这里，每次在启动画面上它都会失败。

感谢您的帮助！

Answer 1

进入Info.plist。很可能您已经为您的应用程序添加了一个标签以支持多个场景（即多个窗口或屏幕）。它应该是这样的：

  <key>UIApplicationSceneManifest</key>
  <dict>
      <key>UIScene Settings</key>
      <dict/>
  </dict>

如果你发现它是这样的，请删除允许多个窗口的键。 UISceneConfigurationsUIApplicationSceneManifest

  <key>UIApplicationSceneManifest</key>
  <dict>
      <key>UIApplicationSupportsMultipleScenes</key>
      <true/>
      <key>UIScene Settings</key>
      <dict/>
  </dict>

这就足够了（你可以避免奇怪的黑屏！）