Flutter firebase，如何检索用户数据并将其显示在地图或列表中

import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

class UserListScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('User List'),
      ),
      body: StreamBuilder<QuerySnapshot>(
        stream: FirebaseFirestore.instance.collection('users').snapshots(),
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            final users = snapshot.data.docs;
            return ListView.builder(
              itemCount: users.length,
              itemBuilder: (context, index) {
                final user = users[index].data();
                return ListTile(
                  title: Text(user['name']),
                  subtitle: Text(user['email']),
                );
              },
            );
          } else if (snapshot.hasError) {
            return Text('Error: ${snapshot.error}');
          } else {
            return CircularProgressIndicator();
          }
        },
      ),
    );
  }
}