如何在flutter中使用函数浏览页面？

import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';

class BrowsePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('浏览页面'),
      ),
      body: Center(
        child: ElevatedButton(
          child: Text('打开网页'),
          onPressed: () {
            _launchURL('https://www.example.com');
          },
        ),
      ),
    );
  }

  void _launchURL(String url) async {
    if (await canLaunch(url)) {
      await launch(url);
    } else {
      throw '无法打开网页：$url';
    }
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'My App',
      home: Scaffold(
        appBar: AppBar(
          title: Text('主页面'),
        ),
        body: Center(
          child: ElevatedButton(
            child: Text('浏览页面'),
            onPressed: () {
              Navigator.push(
                context,
                MaterialPageRoute(builder: (context) => BrowsePage()),
              );
            },
          ),
        ),
      ),
    );
  }
}