参数类型“User”不能分配给参数类型“Future<dynamic>”。？ [复制]

Question

我尝试像往常一样使用 Firebase 实例，但在这种情况下，我遇到了一个错误，我的问题是如何在我的代码中修复此错误：

 The argument type 'User' can't be assigned to the parameter type 'Future<dynamic>'.

class Messages extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      future: FirebaseAuth.instance.currentUser,
      builder: (context, futureSnapshot) {
        if (futureSnapshot.connectionState == ConnectionState.waiting) {
          return Center(
              child: CircularProgressIndicator());
        }
        return StreamBuilder(
            stream: FirebaseFirestore.instance
                .collection('chat')
                .orderBy('created', descending: true)
                .snapshots(),
            builder: (context, chatSnapshot) {
              if (chatSnapshot.connectionState == ConnectionState.waiting) {
                return Center(
                  child: CircularProgressIndicator(),
                );
              }
              final chatdocs = chatSnapshot.data.docs;
              return ListView.builder(
                  itemCount: chatdocs.length,
                  itemBuilder: (context, index) => MessageBubble(
                        chatdocs[index]['text'],
                        chatdocs[index]['userId'] == futureSnapshot.data.uid,
                      ));
         

希望任何人都可以提供帮助。 也许任何人都可以向我解释这一点，而不仅仅是给出答案

Answer 1

FirebaseAuth.instance.currentUser 是 User 类型，它不是 Future。

因此在这种情况下您不需要使用 FutureBuilder。

class Messages extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final currentUser = FirebaseAuth.instance.currentUser;

    return StreamBuilder(
      stream: FirebaseFirestore.instance
          .collection('chat')
          .orderBy('created', descending: true)
          .snapshots(),
      builder: (context, chatSnapshot) {
        if (chatSnapshot.connectionState == ConnectionState.waiting) {
          return Center(
            child: CircularProgressIndicator(),
          );
        }

        final chatdocs = chatSnapshot.data.docs;

        return ListView.builder(
            itemCount: chatdocs.length,
            itemBuilder: (context, index) {
              return MessageBubble(
                chatdocs[index]['text'],
                chatdocs[index]['userId'] == currentUser.data.uid,
              );
            },
        );
      },
    );
  }
}