import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: 'Navigation with Arguments',
        initialRoute: '/',
        routes: {
          '/': (context) => HomeScreen(),
          ArgScreen.routeName: (context) => ArgScreen(),
        });
  }
}

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('Home Screen'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              ElevatedButton(
                child: Text("Navigate to arg passing example screen"),
                onPressed: () {
                  Navigator.pushNamed(
                    context,
                    ArgScreen.routeName,
                    arguments: {
                      'arg1': 'Random Title',
                      'arg2': 'This is a random message',
                    },
                  );
                },
              ),
            ],
          ),
        ));
  }
}

// A Widget that extracts the necessary arguments from the ModalRoute.
class ArgScreen extends StatelessWidget {
  static const routeName = '/argExample';

  @override
  Widget build(BuildContext context) {
    final args = ModalRoute.of(context)!.settings.arguments as Map;

    return Scaffold(
      appBar: AppBar(
        title: Text(args['arg1']),
      ),
      body: Center(
        child: Text(args['arg2']),
      ),
    );
  }
}