fen_expansion_tile

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        primarySwatch: Colors.blue,
      ),
      home: const MyWidget(),
    );
  }
}

class MyWidget extends StatefulWidget {
  const MyWidget({super.key});

  @override
  MyWidgetState createState() => MyWidgetState();
}

class MyWidgetState extends State<MyWidget> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
          leading: GestureDetector(
              onTap: () async {
                setState(() {});
              },
              child: const Icon(Icons.change_circle))),
      body: Column(
        children: [
          ExpansionTile(
            // ビルドする度にkey値を変えることで、ExpansionTileの再生成を促す
            key: GlobalKey(),
            title: const Text('Expansion Tile'),
            leading: const Icon(Icons.ac_unit),
            initiallyExpanded: false,
            children: const [
              ListTile(
                title: Text('ListTile'),
                leading: Icon(Icons.wb_sunny),
              ),
            ],
          )
        ],
      ),
    );
  }
}