如何使用Flutter制作“全选”和“取消全选”按钮？

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^1.0.2

import 'package:flutter/material.dart';

class MyPage extends StatefulWidget {
  @override
  _MyPageState createState() => _MyPageState();
}

class _MyPageState extends State<MyPage> {
  bool _selectAll = false;
  List<bool> _selectedItems = List.generate(10, (index) => false);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('全选和取消全选'),
      ),
      body: ListView.builder(
        itemCount: 10,
        itemBuilder: (context, index) {
          return CheckboxListTile(
            title: Text('选项 $index'),
            value: _selectedItems[index],
            onChanged: (bool value) {
              setState(() {
                _selectedItems[index] = value;
              });
            },
            controlAffinity: ListTileControlAffinity.leading,
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.select_all),
        onPressed: () {
          setState(() {
            _selectAll = !_selectAll;
            _selectedItems = List.generate(10, (index) => _selectAll);
          });
        },
      ),
    );
  }
}

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

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: '全选和取消全选示例',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyPage(),
    );
  }
}