如何使用 FCM 插件正确注册插件

Posted 2023-02-23

【中文标题】如何使用 FCM 插件正确注册插件

【英文标题】：How do I correctly register a plugin with the FCM plugin

【发布时间】：2020-10-30 09:40:55

【问题描述】：

我正在使用https://pub.dev/packages/firebase_messaging v6.0.16 和颤振 v1.17.5

[√] Flutter (Channel stable, v1.17.5, on Microsoft Windows [Version 10.0.18362.900], locale en-US)
 
[√] android toolchain - develop for Android devices (Android SDK version 29.0.3)
[√] Android Studio (version 4.0)
[√] VS Code (version 1.47.0)

我正在尝试在 myBackgroundMessageHandler 中调用 AppAvailability.launchApp('com.companyname.appname'); 处的插件

class CloudMessagingService extends NotificationService 
  final FirebaseMessaging _firebaseMessaging = FirebaseMessaging();

  void configure() 
    if (Platform.isios) _firebaseMessaging.requestNotificationPermissions(IosNotificationSettings());

    _firebaseMessaging.configure(
      onMessage: (Map<String, dynamic> message) async 
        if (isDataNotification(message)) return;
        print('onMessage');
      ,
      onLaunch: (Map<String, dynamic> message) async 
        if (isDataNotification(message)) return;
        print('onLaunch');
      ,
      onResume: (Map<String, dynamic> message) async 
        if (isDataNotification(message)) return;
        print('onResume');
      ,
      onBackgroundMessage: myBackgroundMessageHandler,
    );
  

  static Future<dynamic> myBackgroundMessageHandler(Map<String, dynamic> message) async 
    print('on background message');
    AppAvailability.launchApp('com.companyname.appname'); // it will throw an error when it tries to call the method channel in the app availability plugin
    return message;
  

但我收到以下错误

E/flutter (28000): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: MissingPluginException(No implementation found for method launchApp on channel com.pichillilorenzo/flutter_appavailability)
E/flutter (28000): #0      MethodChannel._invokeMethod 
package:flutter/…/services/platform_channel.dart:154
E/flutter (28000): <asynchronous suspension>
E/flutter (28000): #1      MethodChannel.invokeMethod 
package:flutter/…/services/platform_channel.dart:329
E/flutter (28000): #2      AppAvailability.launchApp 
package:flutter_appavailability/flutter_appavailability.dart:95
E/flutter (28000): #3      CloudMessagingService.myBackgroundMessageHandler 
package:moto_picto/…/firebase/cloud_messaging_service.dart:43
E/flutter (28000): #4      _fcmSetupBackgroundChannel.<anonymous closure> 
package:firebase_messaging/firebase_messaging.dart:38
E/flutter (28000): #5      MethodChannel._handleAsMethodCall 
package:flutter/…/services/platform_channel.dart:409
E/flutter (28000): #6      MethodChannel.setMethodCallHandler.<anonymous closure> 
package:flutter/…/services/platform_channel.dart:377
E/flutter (28000): #7      _DefaultBinaryMessenger.handlePlatformMessage 
package:flutter/…/services/binding.dart:199
E/flutter (28000): #8      _invoke3.<anonymous closure>  (dart:ui/hooks.dart:290:15)
E/flutter (28000): #9      _rootRun  (dart:async/zone.dart:1184:13)
E/flutter (28000): #10     _CustomZone.run  (dart:async/zone.dart:1077:19)
E/flutter (28000): #11     _CustomZone.runGuarded  (dart:async/zone.dart:979:7)
E/flutter (28000): #12     _invoke3  (dart:ui/hooks.dart:289:10)
E/flutter (28000): #13     _dispatchPlatformMessage  (dart:ui/hooks.dart:164:5)

插件在应用程序范围内没有任何问题。我尝试的每个插件都会发生这种情况！

所以我认为问题在于，根据我在这篇文章中的理解，FCM 所做的隔离没有被颤振引擎包裹。

https://github.com/flutter/flutter/issues/13937#issuecomment-656239596

但您需要创建一个自定义的应用程序类，该类挂钩到 插件后台 FlutterNativeView 的初始化。

我确实按照说明将我的 Application.kt 更改为以下内容

package com.companyname.appname
    
import `in`.jvapps.system_alert_window.SystemAlertWindowPlugin
import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService
import io.flutter.view.FlutterMain
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin

import android.os.Build
import android.app.NotificationManager
import android.app.NotificationChannel

public class Application: FlutterApplication(), PluginRegistrantCallback 

   override fun onCreate() 
     super.onCreate();
     FlutterFirebaseMessagingService.setPluginRegistrant(this);
     createNotificationChannels();
     SystemAlertWindowPlugin.setPluginRegistrant(this);
     FlutterMain.startInitialization(this);
   

   override fun registerWith(registry: PluginRegistry) 
    if (!registry!!.hasPlugin("io.flutter.plugins.firebasemessaging")) 
      FirebaseMessagingPlugin.registerWith(registry!!.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
    
    if (!registry!!.hasPlugin("in.jvapps.system_alert_window")) 
      SystemAlertWindowPlugin.registerWith(registry!!.registrarFor("in.jvapps.system_alert_window"));
    
   

   fun createNotificationChannels() 
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) 
        val name = "groupChannel";
        val descriptionText = "This is the group channel";
        val importance = NotificationManager.IMPORTANCE_HIGH;
        val mChannel = NotificationChannel("59054", name, importance);
        mChannel.description = descriptionText;
        val notificationManager = getSystemService(NOTIFICATION_SERVICE) as NotificationManager;
        notificationManager.createNotificationChannel(mChannel);
    
  

还有我的 MainActivity.kt

package com.companyname.appname

import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterActivity() 
    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) 
        GeneratedPluginRegistrant.registerWith(flutterEngine);
    

还有我的 AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.companyname.appname">
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.READ_CONTACTS" />
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE " />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <!-- io.flutter.app.FlutterApplication is an android.app.Application that
         calls FlutterMain.startInitialization(this); in its onCreate method.
         In most cases you can leave this as-is, but you if you want to provide
         additional functionality it is fine to subclass or reimplement
         FlutterApplication and put your custom class here. -->
    <application
        android:name=".Application"
        android:label="App Name"
        android:icon="@mipmap/ic_launcher">
        <activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
            <intent-filter>
                <action android:name="FLUTTER_NOTIFICATION_CLICK" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
        <activity
        android:name="com.yalantis.ucrop.UCropActivity"
        android:screenOrientation="portrait"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar"/>
        <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
        <meta-data
            android:name="com.google.firebase.messaging.default_notification_channel_id"
            android:value="@string/default_notification_channel_id"/>  
    </application>
</manifest>

通知似乎正确显示为抬头通知，我可以调用我的 BackgroundMessageHandler 并执行代码，只是我无法对 myBackgroundMessageHandler 中的任何插件执行任何操作。我正确实施了吗？

它总是会在myBackgroundMessageHandler 中的AppAvailability.launchApp('com.companyname.appname'); 这一行抛出错误，因为如果插件未注册，则隔离无法调用方法通道。

我还查看了这篇 github 帖子

Similar problem

但我的 Application.kt 是这样设置的

我尝试做flutter clean -> 卸载应用程序-> 安装应用程序。问题仍然存在。就像他们在这里描述的那样

MissingPluginException(No implementation found for method show on channel dexterous.com/flutter/local_notifications)

编辑：当我使用 DeviceApp 插件时，也会发生同样的事情。我换了

AppAvailability.launchApp('com.companyname.appname');

与

 DeviceApps.openApp('com.companyname.appname');

于是我在Application.kt的registerWith方法中添加了以下2行，似乎是围绕着缺少插件异常

if (!registry!!.hasPlugin("fr.g123k.deviceapps")) 
  DeviceAppsPlugin.registerWith(registry!!.registrarFor("fr.g123k.deviceapps"));

但错误变为

E/flutter (25583): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: PlatformException(error, Attempt to invoke virtual method 'android.content.pm.PackageManager android.app.Activity.getPackageManager()' on a null object reference, null)
E/flutter (25583): #0      StandardMethodCodec.decodeEnvelope 
package:flutter/…/services/message_codecs.dart:569
E/flutter (25583): #1      MethodChannel._invokeMethod 
package:flutter/…/services/platform_channel.dart:156
E/flutter (25583): <asynchronous suspension>
E/flutter (25583): #2      MethodChannel.invokeMethod 
package:flutter/…/services/platform_channel.dart:329
E/flutter (25583): #3      DeviceApps.openApp 
package:device_apps/device_apps.dart:81
E/flutter (25583): #4      CloudMessagingService.myBackgroundMessageHandler 
package:moto_picto/…/firebase/cloud_messaging_service.dart:73
E/flutter (25583): #5      _fcmSetupBackgroundChannel.<anonymous closure> 
package:firebase_messaging/firebase_messaging.dart:38
E/flutter (25583): #6      MethodChannel._handleAsMethodCall 
package:flutter/…/services/platform_channel.dart:409
E/flutter (25583): #7      MethodChannel.setMethodCallHandler.<anonymous closure> 
package:flutter/…/services/platform_channel.dart:377
E/flutter (25583): #8      _DefaultBinaryMessenger.handlePlatformMessage 
package:flutter/…/services/binding.dart:199
E/flutter (25583): #9      _invoke3.<anonymous closure>  (dart:ui/hooks.dart:290:15)
E/flutter (25583): #10     _rootRun  (dart:async/zone.dart:1184:13)
E/flutter (25583): #11     _CustomZone.run  (dart:async/zone.dart:1077:19)
E/flutter (25583): #12     _CustomZone.runGuarded  (dart:async/zone.dart:979:7)
E/flutter (25583): #13     _invoke3  (dart:ui/hooks.dart:289:10)
E/flutter (25583): #14     _dispatchPlatformMessage  (dart:ui/hooks.dart:164:5)

所以现在它不再说插件丢失，而是说PlatformException(error, Attempt to invoke virtual method 'android.content.pm.PackageManager android.app.Activity.getPackageManager()

编辑 2：

我刚刚注意到最新的错误https://github.com/g123k/flutter_plugin_device_apps/issues/31 可能是插件本身之一。去看看现在不同的插件是否可以工作

我希望我提供了足够的信息，如果需要更多信息或问题是否需要更改，请告诉我。我可以在几分钟内回复。

【参考方案1】：

原来它只是我第一次编辑后的插件！刚刚使用共享偏好进行了尝试，它可以工作！

MY_PACKAGE_NAME

import `in`.jvapps.system_alert_window.SystemAlertWindowPlugin
import fr.g123k.deviceapps.DeviceAppsPlugin

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugin.common.PluginRegistry.PluginRegistrantCallback
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin
import io.flutter.view.FlutterMain
import io.flutter.plugins.firebasemessaging.FlutterFirebaseMessagingService
import io.flutter.plugins.sharedpreferences.SharedPreferencesPlugin

import android.os.Build
import android.app.NotificationManager
import android.app.NotificationChannel

public class Application: FlutterApplication(), PluginRegistrantCallback 

   override fun onCreate() 
     super.onCreate();
     FlutterFirebaseMessagingService.setPluginRegistrant(this);
     SystemAlertWindowPlugin.setPluginRegistrant(this);
     createNotificationChannels();
     FlutterMain.startInitialization(this);
   

   override fun registerWith(registry: PluginRegistry?) 
    if (!registry!!.hasPlugin("io.flutter.plugins.firebasemessaging")) 
      FirebaseMessagingPlugin.registerWith(registry!!.registrarFor("io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin"));
    
    if (!registry!!.hasPlugin("in.jvapps.system_alert_window")) 
      SystemAlertWindowPlugin.registerWith(registry!!.registrarFor("in.jvapps.system_alert_window"));
    
    if (!registry!!.hasPlugin("plugins.flutter.io.shared_preferences")) 
      SharedPreferencesPlugin.registerWith(registry!!.registrarFor("plugins.flutter.io.shared_preferences"));
    
   

   fun createNotificationChannels() 
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) 
        val name = "groupChannel";
        val descriptionText = "This is the group channel";
        val importance = NotificationManager.IMPORTANCE_HIGH;
        val mChannel = NotificationChannel("59054", name, importance);
        mChannel.description = descriptionText;
        val notificationManager = getSystemService(NOTIFICATION_SERVICE) as NotificationManager;
        notificationManager.createNotificationChannel(mChannel);