Flutter用户代理获取插件flutter_user_agentx的使用

flutter_user_agentx 是一个用于在Flutter应用中获取设备用户代理（User-Agent）的插件。它支持从Android和iOS设备中获取用户代理，并且提供了WebView的用户代理信息。

示例User-Agent

额外信息

除了用户代理，该插件还返回一些额外的常量，可用于自定义构建User-Agent。

iOS版本返回的信息：

• isEmulator
• systemName
• systemVersion
• applicationName
• applicationVersion
• buildNumber
• darwinVersion
• cfnetworkVersion
• deviceName
• packageUserAgent

Android版本返回的信息：

• systemName
• systemVersion
• packageName
• shortPackageName
• applicationName
• applicationVersion
• applicationBuildNumber
• packageUserAgent

示例代码

以下是一个完整的示例demo，展示如何使用flutter_user_agentx插件来获取用户代理信息：

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_user_agent/flutter_user_agent.dart';

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

class MyApp extends StatefulWidget {
  [@override](/user/override)
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  String _userAgent = '<unknown>';
  String _webUserAgent = '<unknown>';

  [@override](/user/override)
  void initState() {
    super.initState();
    initUserAgentState();
  }

  // 异步初始化方法
  Future<void> initUserAgentState() async {
    String userAgent, webViewUserAgent;
    try {
      userAgent = await FlutterUserAgent.getPropertyAsync('userAgent');
      await FlutterUserAgent.init();
      webViewUserAgent = FlutterUserAgent.webViewUserAgent;
      print('''
applicationVersion => ${FlutterUserAgent.getProperty('applicationVersion')}
systemName         => ${FlutterUserAgent.getProperty('systemName')}
userAgent          => $userAgent
webViewUserAgent   => $webViewUserAgent
packageUserAgent   => ${FlutterUserAgent.getProperty('packageUserAgent')}
      ''');
    } on PlatformException {
      userAgent = webViewUserAgent = '<error>';
    }

    if (!mounted) return;

    setState(() {
      _userAgent = userAgent;
      _webUserAgent = webViewUserAgent;
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('User agent example app'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text('Device userAgent: $_userAgent'),
              Text('Web userAgent: $_webUserAgent'),
            ],
          ),
        ),
      ),
    );
  }
}