Flutterラボ リリース3周年記念! プロコースが1ヶ月の料金で2ヶ月間受けられる、実質半額セール (2024年3月17日まで・先着)

ListViewと併せて使われることが多いWidgetで、展開と折り畳みができるListTileです。
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool _customTileExpanded = false;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        const ExpansionTile(
          title: Text('ExpansionTile 1'),
          subtitle: Text('Trailing expansion arrow icon'),
          children: <Widget>[
            ListTile(title: Text('This is tile number 1')),
          ],
        ),
        ExpansionTile(
          title: const Text('ExpansionTile 2'),
          subtitle: const Text('Custom expansion arrow icon'),
          trailing: Icon(
            _customTileExpanded
                ? Icons.arrow_drop_down_circle
                : Icons.arrow_drop_down,
          ),
          children: const <Widget>[
            ListTile(title: Text('This is tile number 2')),
          ],
          onExpansionChanged: (bool expanded) {
            setState(() => _customTileExpanded = expanded);
          },
        ),
        const ExpansionTile(
          title: Text('ExpansionTile 3'),
          subtitle: Text('Leading expansion arrow icon'),
          controlAffinity: ListTileControlAffinity.leading,
          children: <Widget>[
            ListTile(title: Text('This is tile number 3')),
          ],
        ),
      ],
    );
  }
}