main.dart

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Route Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: FirstPage(),
       // Initially display FirstPage
      
    );
  }
}

class FirstPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Routing App'),
      ),
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            Text(
              'First Page',
              style: TextStyle(fontSize: 50),
            ),
            RaisedButton(
              child: Text('Go to second'),
              onPressed: () {
                Navigator.pushNamed(context, '/second', arguments: 'Hello World!');
              },
            )
          ],
        ),
      ),
    );
  }
}

class SecondPage extends StatelessWidget {
  final String data;  
  SecondPage(this.data);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Routing App'),
      ),
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: <Widget>[
            Text(
              'Second Page',
              style: TextStyle(fontSize: 50),
            ),
            Text(
              data,
              style: TextStyle(fontSize: 30),
            ),
          ],
        ),
      ),
    );
  }
}