flutter :使用按钮扩展列表视图

import 'package:flutter/material.dart';

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  bool _isExpanded = false;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        ElevatedButton(
          onPressed: () {
            setState(() {
              _isExpanded = !_isExpanded;
            });
          },
          child: Text('展开/折叠'),
        ),
        if (_isExpanded)
          ExpansionListView(
            children: <Widget>[
              // 列表项
              ListTile(
                title: Text('列表项1'),
              ),
              ListTile(
                title: Text('列表项2'),
              ),
              ListTile(
                title: Text('列表项3'),
              ),
            ],
          ),
      ],
    );
  }
}

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Flutter按钮扩展列表视图示例'),
        ),
        body: MyWidget(),
      ),
    );
  }
}