错误：无法在此 ProfileScreen 小部件上方找到正确的 Provider<List<PostModel>>

如何解决错误：无法在此 ProfileScreen 小部件上方找到正确的 Provider<List<PostModel>>

我正在使用 firebase firestore 来保存我的数据，一切正常，直到我达到取回数据的程度为止，一旦我打开屏幕，它就会抛出错误，我试图解决它但不确定有什么问题，如果有人可以帮忙谢谢。

• 这是抛出的错误

Make sure that ProfileScreen is under your MultiProvider/Provider<List<PostModel>>.
  This usually happens when you are creating a provider and trying to read it immediately.

  For example,instead of:

  
  Widget build(BuildContext context) {
    return Provider<Example>(
      create: (_) => Example(),// Will throw a ProviderNotFoundError,because `context` is associated
      // to the widget that is the parent of `Provider<Example>`
      child: Text(context.watch<Example>()),),}
  

  consider using `builder` like so:

  
  Widget build(BuildContext context) {
    return Provider<Example>(
      create: (_) => Example(),// we use `builder` to obtain a new `BuildContext` that has access to the provider
      builder: (context) {
        // No longer throws
        return Text(context.watch<Example>()),}
    ),}

  

• 这是我的代码

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

  @override
  _ProfileScreenState createState() => _ProfileScreenState();
}

class _ProfileScreenState extends State<ProfileScreen> {
  PostService postService = new PostService();
  @override
  Widget build(BuildContext context) {
    List<PostModel> posts = Provider.of<List<PostModel>>(context);
    return StreamProvider<List<PostModel>>.value(
      value: postService.getPosts(FirebaseAuth.instance.currentUser!.uid),initialData: [],child: Scaffold(
        appBar: AppBar(
          title: Text('Posts'),backgroundColor: Colors.blue,body: Container(
          child: ListView.builder(
            itemCount: posts.length,itemBuilder: (context,index){
              return ListTile(
                title: Text(posts[index].creator),subtitle: Text(posts[index].text),);
            },)
    );
  }
}

解决方法

确保您的 ProfileScreen 小部件位于 List 提供者的构建器下

考虑这样使用

ChangeNotifierProvider(
  create: (_) => variable,Builder: (contex,child)=> ProfileScreen() 
)

或尝试使用消费者，