Flutter：使用 patform 通道的 Firebase 消息传递 - 重复的 FlutterActivity

Question

我正在尝试使用 Flutter 实现一个应用程序。该应用程序应该能够使用 FCM 从智能手机向服务器发送消息，或者通过 FCM 从服务器接收消息。我使用 firebase_messaging 插件 (https://pub.dev/packages/firebase_messaging). Everything is working fine for downstream messages (server -> device). Now I tried to add upstream messages (device -> server). As far as I know from the docs, the plugin does not support upstream messages yet. So I began to write native code to send the messages to the server and call this code via platform channel functionality (https://flutter.dev/docs/development/platform-integration/platform-channels?tab=android-channel-kotlin-tab) 实现了 FCM 功能。

初始MainActivity.kt:

import android.os.Bundle

import io.flutter.app.FlutterActivity
import io.flutter.plugins.GeneratedPluginRegistrant

class MainActivity: FlutterActivity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    GeneratedPluginRegistrant.registerWith(this)
  }
}

添加了 Flutter 文档中的方法通道示例。使用 Flutter 文档中指定的导入：

    private val CHANNEL = "samples.flutter.dev/battery"
    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler {
            // Note: this method is invoked on the main thread.
            call, result ->
            if (call.method == "getBatteryLevel") {
                val batteryLevel = getBatteryLevel()

                if (batteryLevel != -1) {
                    result.success(batteryLevel)
                } else {
                    result.error("UNAVAILABLE", "Battery level not available.", null)
                }
            } else {
                result.notImplemented()
            }
        }
    }

    private fun getBatteryLevel(): Int {
        val batteryLevel: Int
        if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
            val batteryManager = getSystemService(Context.BATTERY_SERVICE) as BatteryManager
            batteryLevel = batteryManager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY)
        } else {
            val intent = ContextWrapper(applicationContext).registerReceiver(null, IntentFilter(Intent.ACTION_BATTERY_CHANGED))
            batteryLevel = intent!!.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) * 100 / intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
        }
        return batteryLevel
    }

但不幸的是出现了问题。 firebase_messaging 插件需要 mainactivity.kt 来扩展 io.flutter.app.FlutterActivity。平台频道要求 mainactivity.kt 扩展 io.flutter.embedding.android.FlutterActivity。

有没有办法同时使用 - firebase_messaging 插件和方法渠道？

Answer 1

我将我的代码与 firebase_messaging 插件中的示例项目进行了比较：https://github.com/FirebaseExtended/flutterfire/blob/master/packages/firebase_messaging/example/android/app/src/main/java/io/flutter/plugins/firebasemessagingexample/MainActivity.java

然后我意识到这个例子也使用了io.flutter.embedding.android.FlutterActivity。将导入语句更改为 io.flutter.embedding... 包后，我删除了 GeneratedPluginRegistrant.registerWith(this)，因为 GeneratedPluginRegistrant 是从 io.flutter.plugins.GeneratedPluginRegistrant 导入的，似乎与嵌入包不匹配。然后我再次检查了 io.flutter.embedding.engine.FlutterEngine 中的字段和函数并添加了以下行： flutterEngine?.plugins?.add(FirebaseMessagingPlugin())

在此之后，我重新编译了应用程序，并在开始时成功打印出 FCM 设备 ID 和电池状态。

import android.content.Context
import android.content.ContextWrapper
import android.content.Intent
import android.content.IntentFilter
import android.os.BatteryManager
import android.os.Build.VERSION
import android.os.Build.VERSION_CODES
import android.os.Bundle
import androidx.annotation.NonNull
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.MethodChannel
import io.flutter.plugins.firebasemessaging.FirebaseMessagingPlugin

class MainActivity : io.flutter.embedding.android.FlutterActivity() {

    private val CHANNEL = "samples.flutter.dev/battery"

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        flutterEngine?.plugins?.add(FirebaseMessagingPlugin())
    }

    override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) {
        MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler {
            // Note: this method is invoked on the main thread.
            call, result ->
            if (call.method == "getBatteryLevel") {
                val batteryLevel = getBatteryLevel()

                if (batteryLevel != -1) {
                    result.success(batteryLevel)
                } else {
                    result.error("UNAVAILABLE", "Battery level not available.", null)
                }
            } else {
                result.notImplemented()
            }
        }
    }

    private fun getBatteryLevel(): Int {
        val batteryLevel: Int
        if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
            val batteryManager = getSystemService(Context.BATTERY_SERVICE) as BatteryManager
            batteryLevel = batteryManager.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY)
        } else {
            val intent = ContextWrapper(applicationContext).registerReceiver(null, IntentFilter(Intent.ACTION_BATTERY_CHANGED))
            batteryLevel = intent!!.getIntExtra(BatteryManager.EXTRA_LEVEL, -1) * 100 / intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1)
        }
        return batteryLevel
    }
}

Flutter：使用 patform 通道的 Firebase 消息传递 - 重复的 FlutterActivity

Flutter: Firebase messaging with patform channels - Duplicated FlutterActivity

android

firebase

flutter

firebase-cloud-messaging