在顫振中發送導航器中的提供者

我正在創建一個關于 Flutter 和 Firestore 中購物清單的應用程式。我現在正在嘗試使用 bloc 模式，當我按下一個按鈕時，我想導航到另一個螢屏以創建一個新串列，如果我按下另一個按鈕，我想在該螢屏上呼叫 bloc 和業務邏輯來創建一個新的購物清單，然后回傳螢屏，顯示用戶的所有購物清單。

這是我呼叫 MultiBlocProvider 的主要部分。現在我有 blocProviders 一個用于身份驗證，另一個用于購物清單。

Widget build(BuildContext context) {
FirebaseFunctions functions = FirebaseFunctions.instance;

return MaterialApp(
  title: 'Flutter Demo',
  theme: ThemeData(primarySwatch: Colors.blue),
  debugShowCheckedModeBanner: false,
  home: MultiBlocProvider(
    providers: [
     BlocProvider(
        create: (context) => AuthBloc(FirebaseAuthProvider())),
     BlocProvider(
        create: (context) => ShoppingBloc(FirebaseCloudStorage()),

     )],
    child: const HomePage(),
    ),
  routes: {
    createOrUpdateNoteRoute: (context) => const CreateUpdateNoteView(),
    createOrUpdateShoppingCartListRoute: (context) => const CreateUpdateShoppingCartListView(),
  },
);

這是當我按下時我想導航到不同螢屏的按鈕：

IconButton(
          onPressed: () {

            Navigator.push(context,
                MaterialPageRoute(
                    builder: (context) =>
                  BlocProvider<ShoppingBloc>.value(
                    value: context.read<ShoppingBloc>(),
                    child: const CreateUpdateShoppingCartListView(),
                  )
                ),
            );
          },
          icon: const Icon(Icons.add),
        ),

這是我稱之為集團的觀點：

    @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('New shopping cart list'),
          actions: [
            IconButton(
              onPressed: () {
                final text = _textController.text;
                final ownerUserId = currentUser.id;
                context.read<ShoppingBloc>()
                    .add(ShoppingCreateNewShoppingCartEvent(ownerUserId, 'creating a new list'));
              },
              icon: const Icon(Icons.add),
            ),                 
          ],
        ),
        body: Column(children: [
          TextField(
          controller: _textController,
          keyboardType: TextInputType.multiline,
          maxLines: null,
          textInputAction: TextInputAction.go,
          decoration: const InputDecoration(
            hintText: 'Start typing you shopping cart name...',
          ),
          ),
        ],
        ),
      );

這是集團：

class ShoppingBloc extends Bloc<ShoppingEvent, ShoppingState> {

ShoppingBloc(FirebaseCloudStorage provider) : super(ShoppingInitial()) {

on<ShoppingCreateNewShoppingCartEvent>((event, emit) async{
  final ownerUserId = event.ownerUserId;
  final name = event.name;

  try {
    provider.createNewShoppingCartList(ownerUserId: ownerUserId, name: name);
    emit(const StateCreateShoppingCart());
  } catch (e){
    print('There was an error in createNewShoppingCartEvent in bloc');
  }
 });
 }

}

事件：

class ShoppingCreateNewShoppingCartEvent extends ShoppingEvent{
 final String ownerUserId;
 final String name;

const ShoppingCreateNewShoppingCartEvent(this.ownerUserId, this.name);
}

這就是狀態：

class StateCreateShoppingCart extends ShoppingState {
  const StateCreateShoppingCart();
}

我收到錯誤訊息Could not find the correct Provider<ShoppingBloc> above this Builder Widget。我嘗試了多種解決方案，但沒有一個奏效。我認為 中的提供者與 中shoppingCartView的提供者不同，CreateUpdateShoppingCartListView所以我想在導航器中傳遞這個提供者還是有更好的解決方案？

提前致謝。

uj5u.com熱心網友回復：

您已經在 MaterialApp 中提供了 ShoppingBloc，但也嘗試在此處提供新的 bloc：

BlocProvider<ShoppingBloc>.value(
value: context.read<ShoppingBloc>(),
child: const CreateUpdateShoppingCartListView(),
)

...那很糟...

試試這個.. 正確添加命名路由并從MaterialApp中移除MultiBlocProvider

Widget build(BuildContext context) {
FirebaseFunctions functions = FirebaseFunctions.instance;

return MultiBlocProvider(
    providers: [
     BlocProvider(
        create: (context) => AuthBloc(FirebaseAuthProvider())),
     BlocProvider(
        create: (context) => ShoppingBloc(FirebaseCloudStorage()),

     ),
    ], 
  child: MaterialApp(
     title: 'Flutter Demo',
     theme: ThemeData(primarySwatch: Colors.blue),
     debugShowCheckedModeBanner: false,
     home: const HomePage(),
     routes: {
       "/createOrUpdateNote": (context) => const CreateUpdateNoteView(),
       "/shopingCartListRoute": (context) => const CreateUpdateShoppingCartListView(),
     },
  ),
);

然后你可以像這樣導航

IconButton(
          onPressed: () {
            Navigator.pushNamed(context, '/shopingCartListRoute');
          },
          icon: const Icon(Icons.add),
        )

然后使用您提供的塊（您提供的示例似乎還可以）

  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('New shopping cart list'),
          actions: [
            IconButton(
              onPressed: () {
                final text = _textController.text;
                final ownerUserId = currentUser.id;
                context.read<ShoppingBloc>()
                    .add(ShoppingCreateNewShoppingCartEvent(ownerUserId, 'creating a new list'));
              },
              icon: const Icon(Icons.add),
            ),                 
          ],
        ),
        body: Column(children: [
          TextField(
          controller: _textController,
          keyboardType: TextInputType.multiline,
          maxLines: null,
          textInputAction: TextInputAction.go,
          decoration: const InputDecoration(
            hintText: 'Start typing you shopping cart name...',
          ),
          ),
        ],
        ),
      );

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