有什么方法可以在 riverpod 的提供程序中传递参数

Is there any ways to pass parameters in riverpod's provider

如何将 FirebaseAuth 用户传递给 riverpod 中的 StreamProvider?

使用旧的提供程序包时, 我曾经从 FirebaseAuth 获取 user.uid 并将变量传递给 StreamProvider,如果我们可以获得 user.uid.

则返回 StreamProvider
@override
  Widget build(BuildContext context) {
    final FirebaseAuthService authService =
        Provider.of<FirebaseAuthService>(context, listen: false);
    return StreamBuilder<User>(
      stream: authService.onAuthStateChanged,
      builder: (BuildContext context, AsyncSnapshot<User> snapshot) {
        final User loggedInUser = snapshot.data;
        if (loggedInUser != null) {
          final String userId = loggedInUser.userId;
          return MultiProvider(
            providers: <SingleChildWidget>[
              StreamProvider<User>(
                initialData: User.initialData(),
                create: (_) => DB.instance.getLoggedInUserStream(
                  loggedInUserId: userId,
                ),

您可以使用 Riverpod 的 family 功能。

final user = StreamProvider.family<User, String>((ref, uid) {
  // use uid to get User
  return User;
});

然后使用提供商:

useProvider(user(uid));

或者,您可以 read the value 直接从您的 FirebaseAuthService 提供商那里获得用户提供商。

final user = StreamProvider<User>((ref) {
  final stream = ref.watch(FirebaseAuthService.stream);
  // get uid from stream data
  return User;
});

使用 family 修饰符将外部值传递给提供者。

final userStreamProvider = StreamProvider.family<User, String>((ref, uid) {
  return User(id: uid);
}); 

使用provider时,需要传值给userStreamProvider

对于 flutter_riverpod 用户,

Widget build(BuildContext context, ScopedReader watch) {
  final user = watch(userStreamProvider(uid));
}

对于 hooks_riverpod 用户,

Widget build(BuildContext) {
  final user = useProvider(userStreamProvider(uid));
}