navigate_with_specified_arguments.dart

// Copyright 2019 the Dart project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file.

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',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        colorSchemeSeed: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
      onGenerateRoute: (settings) {
        if (settings.name == '/detail') {
          assert(
            settings.arguments != null &&
                settings.arguments is CounterArguments,
          );

          final CounterArguments arguments =
              settings.arguments! as CounterArguments;

          return MaterialPageRoute(
            builder: (_) => CountDetailScreen(
              arguments.count,
            ),
          );
        }

        return null;
      },
    );
  }
}

class MyHomePage extends StatefulWidget {
  final String title;

  const MyHomePage({
    super.key,
    required this.title,
  });

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

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  void navigateToDetail(
    BuildContext context,
    int count,
  ) async {
    if (!context.mounted) {
      return;
    }

    return Navigator.of(context).pushNamed<void>(
      '/detail',
      arguments: CounterArguments(count),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          FloatingActionButton(
            onPressed: () => navigateToDetail(context, _counter),
            tooltip: 'To Detail',
            child: const Icon(Icons.airplanemode_active),
            heroTag: 'detail',
          ),
          const SizedBox(height: 8),
          FloatingActionButton(
            onPressed: _incrementCounter,
            tooltip: 'Increment',
            child: const Icon(Icons.add),
            heroTag: 'add',
          ),
        ],
      ),
    );
  }
}

abstract class RouteArguments extends Object {
  const RouteArguments();
}

class CounterArguments extends RouteArguments {
  const CounterArguments(this.count);

  final int count;
}

class CountDetailScreen extends StatelessWidget {
  const CountDetailScreen(this.count, {super.key});

  final int count;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      
      appBar: AppBar(automaticallyImplyLeading: true),
      body: Center(
        child: Text('$count'),
      ),
    );
  }
}