Flutter:从Firebase刷新时获取用户数据

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

class UserProfile extends StatefulWidget {
  @override
  _UserProfileState createState() => _UserProfileState();
}

class _UserProfileState extends State<UserProfile> {
  final FirebaseAuth _auth = FirebaseAuth.instance;
  User? user;
  late Stream<DocumentSnapshot> _userStream;

  @override
  void initState() {
    super.initState();
    user = _auth.currentUser;
    if (user != null) {
      _userStream = FirebaseFirestore.instance
          .collection('users')
          .doc(user!.uid)
          .snapshots();
    }
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<DocumentSnapshot>(
      stream: _userStream,
      builder: (context, snapshot) {
        if (snapshot.hasData && snapshot.data != null) {
          var userData = snapshot.data!.data() as Map<String, dynamic>;
          return Scaffold(
            appBar: AppBar(title: Text('User Profile')),
            body: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text('Name: ${userData['name']}'),
                  Text('Email: ${userData['email']}'),
                  // 其他用户数据...
                ],
              ),
            ),
          );
        } else {
          return CircularProgressIndicator();
        }
      },
    );
  }
}