Flutter消息处理插件firebase_messaging_handler的使用

如果你对处理Firebase Cloud Messaging (FCM) 通知感到困扰，那么firebase_messaging_handler插件将会是一个不错的选择。它旨在简化FCM的通知管理过程。

主要优点

• 统一流：所有通知点击回调（包括已终止、后台和前台状态）都通过一个易于管理的流传递。
• 优化的后端调用：确保FCM更新到后端的回调仅触发一次，避免不必要的API请求。
• 用户友好的权限处理：智能地请求通知权限，提供流畅的用户体验。

安装步骤

添加依赖

首先，在你的pubspec.yaml文件中添加firebase_messaging_handler包依赖。这个插件已经包含了必要的功能，所以你不需要单独添加firebase_messaging或flutter_local_notifications依赖。

dependencies:
  firebase_messaging_handler: ^版本号

针对Android和iOS的具体修改

Android

在android/app/src/main/AndroidManifest.xml文件的<manifest>部分添加以下权限和接收器：

<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.VIBRATE" /> 

<application>
    <meta-data
        android:name="com.google.firebase.messaging.default_notification_icon"
        android:resource="@drawable/ic_notification" />
    <receiver android:exported="false" android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />
    <receiver android:exported="false" android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED"/>
            <action android:name="android.intent.action.MY_PACKAGE_REPLACED"/>
            <action android:name="android.intent.action.QUICKBOOT_POWERON" />
            <action android:name="com.htc.intent.action.QUICKBOOT_POWERON"/>
        </intent-filter>
    </receiver>
</application>

为了启用多Dex支持，请在android/app/build.gradle中添加：

android {
defaultConfig {
    ...
    multiDexEnabled true
    ...
}
...
dependencies {
...
implementation "androidx.multidex:multidex:2.0.1"
...
}

iOS

1. 在Apple Developer Portal注册你的应用，并为你的App ID添加推送通知功能。
2. 确保在Xcode中正确初始化Firebase，并启用推送通知和后台模式能力。
3. 在AppDelegate中初始化Firebase。

初始化Firebase

在应用的main函数中初始化Firebase后立即添加以下代码行：

await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);
await FirebaseMessagingHandler.instance.checkInitial();

示例Demo

下面是一个完整的示例，展示了如何使用firebase_messaging_handler来初始化和处理通知：

import 'dart:developer';
import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_messaging_handler/firebase_messaging_handler.dart';
import 'package:flutter/material.dart';
import 'firebase_options.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );

  await FirebaseMessagingHandler.instance.checkInitial();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Firebase Messaging Handler Example',
      home: NotificationScreen(),
    );
  }
}

class NotificationScreen extends StatefulWidget {
  const NotificationScreen({Key? key}) : super(key: key);

  @override
  State<NotificationScreen> createState() => _NotificationScreenState();
}

class _NotificationScreenState extends State<NotificationScreen> {
  late FirebaseMessagingHandler _messagingHandler;
  String? _currentPayload;
  bool _showClearButton = true;

  @override
  void initState() {
    _initFirebaseMessagingHandler();
    super.initState();
  }

  Future<void> _initFirebaseMessagingHandler() async {
    _messagingHandler = FirebaseMessagingHandler.instance;
    Stream<NotificationData?>? clickStream = await _messagingHandler.init(
      androidChannelList: [
        NotificationChannelData(
          id: 'android_notification_channel_id',
          name: 'name can be anything',
          importance: NotificationImportanceEnum.max,
          priority: NotificationPriorityEnum.high,
        ),
      ],
      androidNotificationIconPath: '@drawable/ic_notification',
      senderId: DefaultFirebaseOptions.android.messagingSenderId,
      updateTokenCallback: (final String fcmToken) async {
        log('FCM Token: $fcmToken');
        setState(() {
          _showClearButton = true;
        });
        print('FCM Token: $fcmToken');

        return Future.value(true);
      },
    );

    if (clickStream != null) {
      clickStream.listen((NotificationData? data) {
        if (data != null) {
          setState(() {
            _currentPayload =
                (data.payload.isNotEmpty ? data.payload : '').toString();
          });
        }
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Handler Example'),
        centerTitle: true,
        actions: [
          InkWell(
            onTap: () async {
              await _messagingHandler.clearToken();
              await _initFirebaseMessagingHandler();
            },
            child: const Padding(
              padding: EdgeInsets.only(right: 20, left: 10),
              child: Icon(Icons.restart_alt),
            ),
          ),
        ],
      ),
      body: Center(
        child: Text(
          'Current Payload: \n$_currentPayload',
          textAlign: TextAlign.center,
        ),
      ),
      floatingActionButtonLocation: FloatingActionButtonLocation.centerFloat,
      floatingActionButton: Row(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          if (_showClearButton)
            Padding(
              padding: const EdgeInsets.only(right: 20),
              child: ElevatedButton(
                style: ElevatedButton.styleFrom(backgroundColor: Colors.blue),
                onPressed: () async {
                  await _messagingHandler.clearToken();
                  setState(() {
                    _showClearButton = false;
                  });
                },
                child: const Text(
                  'Clear Token',
                  style: TextStyle(color: Colors.white),
                ),
              ),
            ),
          ElevatedButton(
            style: ElevatedButton.styleFrom(backgroundColor: Colors.blue),
            onPressed: () {
              setState(() {
                _currentPayload = null;
              });
            },
            child: const Text(
              'Clear Payload',
              style: TextStyle(color: Colors.white),
            ),
          ),
        ],
      ),
    );
  }
}

这段代码展示了如何集成firebase_messaging_handler插件，初始化通知监听，并根据接收到的通知数据更新UI。