【Flutter/Dart】シンプルなアラートビューを出す

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyButtonPage(),
    );
  }
}

class MyButtonPage extends StatelessWidget {
  void _showAlertDialog(BuildContext context) {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          title: Text('Alert'),
          content: Text('This is an alert message.'),
          actions: [
            TextButton(
              onPressed: () {
                Navigator.of(context).pop(); // Close the dialog
              },
              child: Text('OK'),
            ),
          ],
        );
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Button with Alert Example'),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            _showAlertDialog(
                context); // Show the alert when the button is tapped
          },
          child: Text('Show Alert'),
        ),
      ),
    );
  }
}