如何在浏览器中打开已安装的应用程序并打开url_launcher？

dependencies:
  url_launcher: ^6.0.0

import 'package:url_launcher/url_launcher.dart';

bool canLaunchUrl = await canLaunch(url);

if (canLaunchUrl) {
  await launch(url);
} else {
  throw '无法打开URL：$url';
}

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

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'URL Launcher示例',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  final String url = 'https://www.example.com';

  Future<void> _launchURL() async {
    bool canLaunchUrl = await canLaunch(url);
    if (canLaunchUrl) {
      await launch(url);
    } else {
      throw '无法打开URL：$url';
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('URL Launcher示例'),
      ),
      body: Center(
        child: ElevatedButton(
          onPressed: _launchURL,
          child: Text('打开URL'),
        ),
      ),
    );
  }
}