要从“initState()”异步初始化的提供程序,但get'找不到正确的提供程序`

我开发了一个广告应用程序,在详细视图上有一个消息按钮。

当用户点击它时,聊天视图(有状态的小部件)就会被推到屏幕上。

initState()用于调用 asyncInitMessages() 其从远程数据库异步地获取聊天和相关消息。这个 异步初始化消息() 属于 Chats 扩展的类 ChangeNotifier 。

/// A chat conversation
class Chats extends ChangeNotifier {
  /// Internal, private state of the chat.


  void asyncInitMessages(
      {required ClassifiedAd ad,
      required String watchingUserId,
      required bool isOwner}) async {

     // blah blah
  }
}

这个 ClassifiedAdMessagesView 有状态的小部件类实现如下(snippt):

  @override
  void initState() {
    
    // == Fetch conversation and messages 
    asyncInitMessages();

  }


void asyncInitMessages() async {
    // === Update all messages
    try {
      Provider.of<Chats>(context, listen: false).asyncInitMessages(
          ad: widget.ad,
          watchingUserId: widget.watchingUser!.uid,
          isOwner: _isOwner);
    } catch (e) {
      if (mounted) {
        setState(() {
          _error = "$e";
          _ready = true;
        });
      }
    }
  }


  @override
  Widget build(BuildContext context) {
    // <<<<<<<<<<< The exception fires at the Consumer line right below
    return Consumer<Chats>(builder: (context, chats, child) {
      return Scaffold(
        // ... blah blah 

最后,当运行所有这些时,我在 Consumer 线路:

找不到正确的提供程序<聊天>

非常感谢您的帮助。

[更新]

这是主屏幕(离信息屏幕很远)

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  //if (Firebase.apps.isEmpty) {
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );
  // } else {
  //   Firebase.app(); // if already initialized, use that one
  // }
  if (USE_DATABASE_EMULATOR) {
    FirebaseDatabase.instance.useDatabaseEmulator(emulatorHost, emulatorPort);
  }

  runApp(RootRestorationScope(
      restorationId: 'root',
      child: ChangeNotifierProvider(
          create: (context) => StateModel(),
          child: const App())));
}


class App extends StatefulWidget {
  const App({super.key});
  @override
  State<App> createState() => _AppState();
}

class _AppState extends State<App> {

  @override
  Widget build(BuildContext context) {
    return PersistedAppState(
        storage: const JsonFileStorage(),
        child: MultiProvider(
            providers: [
              ChangeNotifierProvider<ThemeModel>.value(value: _themeModel),
              //ChangeNotifierProvider<AuthModel>.value(value: _auth),
            ],
            child: Consumer<ThemeModel>(
                builder: (context, themeModel, child) => MaterialApp(
                  // blah blah

    }
  }
}

而位于

/// Classified ad detail view
class ClassifiedAdDetailView extends StatefulWidget {
  final User? watchingUser;
  final ClassifiedAd ad;

  const ClassifiedAdDetailView(
      {Key? key, required this.watchingUser, required this.ad})
      : super(key: key);

  @override
  State<ClassifiedAdDetailView> createState() => _ClassifiedAdDetailViewState();
}

class _ClassifiedAdDetailViewState extends State<ClassifiedAdDetailView>
    with TickerProviderStateMixin {

 @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
        create: (context) => Chats(),
        builder: ((context, child) => Scaffold(

// blah blah

          ElevatedButton(
            onPressed: () => Navigator.of(context).push(MaterialPageRoute(
                                builder: (context) => ClassifiedAdMessagesView(
                                    ad: ad,
                                    watchingUser: widget.watchingUser)));
                          }),