「.NET 開発基盤部会 Wiki」は、「Open棟梁Project」,「OSSコンソーシアム .NET開発基盤部会」によって運営されています。
2026年、リブートはFlutterデスクトップ(Windows)で実施
flutter --version dart --version
CMD / PowerShell?で
Windowsデスクトップ対応を有効化
flutter config --enable-windows-desktop
依存関係の確認
flutter doctor
CMD / PowerShell?で
flutter create my_app
cd my_app
flutter run -d windows
VS Code上から、
ココまでの導入手順もAIに生成させている。
以下はプロンプト
以下で生成したコードを修正して3分割のヘッダ、左メニュー、メインエリアの画面を作成したい。 なお、左メニューのリンクを押下するとメインエリアが画面遷移するものとする。 flutter create my_app 修正内容を教えてください。
ページのファイルは分割したい。
以下は、出力から修正ポイントを抜粋したもの。
lib/
├── main.dart
├── layout/
│ └── main_layout.dart
└── pages/
├── page_home.dart
├── page_about.dart
└── page_settings.dart
import 'package:flutter/material.dart';
import 'layout/main_layout.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'My App',
theme: ThemeData(
colorScheme: ColorScheme.fromSeed(seedColor: Colors.blue),
useMaterial3: true,
),
home: const MainLayout(),
);
}
}import 'package:flutter/material.dart';
import '../pages/page_home.dart';
import '../pages/page_about.dart';
import '../pages/page_settings.dart';
import '../pages/page_contact.dart';
class MainLayout extends StatefulWidget {
const MainLayout({super.key});
@override
State<MainLayout> createState() => _MainLayoutState();
}
class _MainLayoutState extends State<MainLayout> {
int _selectedIndex = 0;
final List<Map<String, dynamic>> _menuItems = [
{'icon': Icons.home, 'label': 'ホーム'},
{'icon': Icons.info, 'label': '概要'},
{'icon': Icons.settings, 'label': '設定'},
];
final List<Widget> _pages = const [
PageHome(),
PageAbout(),
PageSettings(),
];
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Theme.of(context).colorScheme.primary,
title: const Text(
'My Application',
style: TextStyle(color: Colors.white, fontWeight: FontWeight.bold),
),
actions: [
IconButton(
icon: const Icon(Icons.notifications, color: Colors.white),
onPressed: () {},
),
IconButton(
icon: const Icon(Icons.account_circle, color: Colors.white),
onPressed: () {},
),
],
),
body: Row(
children: [
NavigationRail(
selectedIndex: _selectedIndex,
onDestinationSelected: (int index) {
setState(() {
_selectedIndex = index;
});
},
labelType: NavigationRailLabelType.all,
destinations: _menuItems.map((item) {
return NavigationRailDestination(
icon: Icon(item['icon'] as IconData),
label: Text(item['label'] as String),
);
}).toList(),
),
const VerticalDivider(thickness: 1, width: 1),
Expanded(
child: _pages[_selectedIndex],
),
],
),
);
}
}ホントは、page_contact.dartもあったが割愛。
もともとあったIncrement機能が消失したので、page_counter.dartとして追加。
既存のIncrement機能が消失したのでCounterとして追加して下さい。
```
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// TRY THIS: Try running your application with "flutter run". You'll see
// the application has a purple toolbar. Then, without quitting the app,
// try changing the seedColor in the colorScheme below to Colors.green
// and then invoke "hot reload" (save your changes or press the "hot
// reload" button in a Flutter-supported IDE, or press "r" if you used
// the command line to start the app).
//
// Notice that the counter didn't reset back to zero; the application
// state is not lost during the reload. To reset the state, use hot
// restart instead.
//
// This works for code too, not just values: Most code changes can be
// tested with just a hot reload.
colorScheme: .fromSeed(seedColor: Colors.deepPurple),
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// TRY THIS: Try changing the color here to a specific color (to
// Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
// change color while the other colors stay the same.
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
//
// TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
// action in the IDE, or press "p" in the console), to see the
// wireframe for each widget.
mainAxisAlignment: .center,
children: [
const Text('You have pushed the button this many times:'),
Text(
'$_counter',
style: Theme.of(context).textTheme.headlineMedium,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
),
);
}
}
```
main_layout.dart
_menuItems と _pages にCounterを追記
page_counter.dart
import 'package:flutter/material.dart';
class PageCounter extends StatefulWidget {
const PageCounter({super.key});
@override
State<PageCounter> createState() => _PageCounterState();
}
class _PageCounterState extends State<PageCounter> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
const Icon(Icons.touch_app, size: 64, color: Colors.teal),
const SizedBox(height: 16),
const Text('ボタンを押した回数:'),
Text(
'$_counter',
style: Theme.of(context).textTheme.headlineMedium,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
),
);
}
}