Flutter Firebase Cloud Messaging onMessage被触发两次

Question

我已经实现了firebase_messaging flutter软件包建议的基本配置。但是，每次我在flutter应用程序onMessage上收到通知时，都会触发两次。我正在使用firebase_messaging 6.0.9，Dart 2.7.0和Flutter 1.12.13 + hotfix.5。

这是我的[project] /android/build.gradle

    buildscript {
    repositories {
        google()
        jcenter()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:3.5.0'
        classpath 'com.google.gms:google-services:4.3.2'
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

rootProject.buildDir = '../build'
   subprojects {
       project.buildDir = "${rootProject.buildDir}/${project.name}"
   }
   subprojects {
       project.evaluationDependsOn(':app')
   }

   task clean(type: Delete) {
       delete rootProject.buildDir
   }

这是我的[project] /android/app/build.gradle

def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
        localProperties.load(reader)
    }
}

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
    flutterVersionCode = '1'
}

def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
    flutterVersionName = '1.0'
}

apply plugin: 'com.android.application'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

android {
    compileSdkVersion 28

    lintOptions {
        disable 'InvalidPackage'
    }

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.chat_notification"
        minSdkVersion 16
        targetSdkVersion 28
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.debug
        }
    }
}

flutter {
    source '../..'
}

dependencies {
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
}

apply plugin: 'com.google.gms.google-services'

这是两次onMessage触发的代码

import 'package:chat_notification/model/message.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/material.dart';

class MessageWidget extends StatefulWidget {
  @override
  _MessageWidgetState createState() => _MessageWidgetState();
}

class _MessageWidgetState extends State<MessageWidget> {

  FirebaseMessaging _firebaseMessaging = FirebaseMessaging();
  List<Message> messages = [];

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _firebaseMessaging.configure(
      onMessage: (Map<String, dynamic> response) async {
        print("onMessage: $response");
      },
      onLaunch: (Map<String, dynamic> response) async {
        print("onLaunch: $response");
      },
      onResume: (Map<String, dynamic> response) async {
        print("onResume: $response");
      },
    );
  }

  @override
  Widget build(BuildContext context) => ListView(
    children: messages.map(buildMessage).toList(),
  );

  Widget buildMessage(Message message) => ListTile(
    title: Text(message.title),
    subtitle: Text(message.body),
  );
}

我已经尝试创建新项目，但是似乎每个项目都会发生。如果有人可以帮助我，我将不胜感激。

编辑：

最新版本的firebase_messaging：7.0.0中不再提供此功能。我发现最好的解决方案是更新程序包。重复的消息不再存在。

Answer 1

这是此问题的理想代码。 我们只需要声明一个静态布尔变量，它将与onResume（）一起使用。 在只缺少某些逻辑之前，这就是为什么它要调用两次。 现在，它为我工作。希望您也能从中获得帮助。

onMessage: // ignore: missing_return (Map<String, dynamic> msg) { if(!isNotified) { print("onMessage called"); print(msg); DocumentReference documentReference = Firestore.instance.collection('PushNotifications').document(); documentReference.setData({ "payload": msg }); } isNotified = !isNotified; }

Github Link

Answer 2

我遇到了同样的问题，原因是最近我将项目重命名。我注意到（过长的时间），其中一个通知标语中说的是旧应用程序名称，另一个是新的应用程序名称。卸载并重新安装应用程序（以及flutter clean）后，双重通知消失了。

简而言之，如果没有其他效果，请尝试再次卸载并重新安装您的应用。

Answer 3

更新到最新的 FireFlutter 包解决了这个问题：

对于非空安全：

firebase_messaging: ^8.0.0-dev.15
firebase_core: ^0.7.0