如何在flutter firestore provider中显示数据

dependencies:
  flutter:
    sdk: flutter
  cloud_firestore: ^2.5.3
  provider: ^6.0.1

class Task {
  final String id;
  final String title;
  final bool completed;

  Task({required this.id, required this.title, required this.completed});
}

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

class TaskProvider extends ChangeNotifier {
  final CollectionReference _tasksCollection =
      FirebaseFirestore.instance.collection('tasks');

  List<Task> _tasks = [];

  List<Task> get tasks => _tasks;

  Future<void> fetchTasks() async {
    try {
      final QuerySnapshot snapshot = await _tasksCollection.get();
      _tasks = snapshot.docs.map((doc) {
        final data = doc.data() as Map<String, dynamic>;
        return Task(
          id: doc.id,
          title: data['title'],
          completed: data['completed'],
        );
      }).toList();
      notifyListeners();
    } catch (e) {
      print('Error fetching tasks: $e');
    }
  }
}

void main() {
  runApp(
    ChangeNotifierProvider(
      create: (context) => TaskProvider(),
      child: MyApp(),
    ),
  );
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Firestore Provider Demo',
      home: HomePage(),
    );
  }
}

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

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    final taskProvider = Provider.of<TaskProvider>(context);
    final tasks = taskProvider.tasks;

    return Scaffold(
      appBar: AppBar(
        title: Text('Tasks'),
      ),
      body: ListView.builder(
        itemCount: tasks.length,
        itemBuilder: (context, index) {
          final task = tasks[index];
          return ListTile(
            title: Text(task.title),
            subtitle: Text(task.completed ? 'Completed' : 'Not Completed'),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          taskProvider.fetchTasks();
        },
        child: Icon(Icons.refresh),
      ),
    );
  }
}