尝试在颤动中使用自定义EventChannel时的MissingPluginException

Question

最近我决定创建flutter应用程序，我只有一个问题。

我想创建自定义流来检测耳机拔下以停止音乐播放。

这是我的MainActivity。

package com.example.radio24

import android.content.BroadcastReceiver
import android.content.IntentFilter
import android.content.Context
import android.content.Intent
import android.media.AudioManager
import android.os.Bundle
import android.os.PersistableBundle
import io.flutter.embedding.android.FlutterActivity
import io.flutter.plugin.common.EventChannel

class MainActivity: FlutterActivity() {
    private val HEADPHONES_LISTENER_CHANNEL = "com.radioanime24.dev/headphones"
    lateinit var broadCastReceiver: BroadcastReceiver;
    override fun onCreate(savedInstanceState: Bundle?, persistentState: PersistableBundle?) {
        super.onCreate(savedInstanceState, persistentState)
        EventChannel(flutterEngine?.dartExecutor?.binaryMessenger, HEADPHONES_LISTENER_CHANNEL).setStreamHandler(
                object: EventChannel.StreamHandler {
                    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
                        broadCastReceiver = object : BroadcastReceiver() {
                            override fun onReceive(contxt: Context?, intent: Intent?) {
                                when (intent?.action) {
                                    AudioManager.ACTION_AUDIO_BECOMING_NOISY -> {
                                        events?.success("HEADPHONES_UNPLUGGED")
                                    }
                                }
                            }
                        }
                        val filter = IntentFilter(AudioManager.ACTION_AUDIO_BECOMING_NOISY)
                        registerReceiver(broadCastReceiver, filter);
                    }
                    override fun onCancel(arguments: Any?) {
                        unregisterReceiver(broadCastReceiver)
                    }
                }
        )
    }
}

在dart中，我尝试使用以下命令来处理此流：

    Stream headPhonesStateStream = EventChannel('com.radioanime24.dev/headphones').receiveBroadcastStream();
    headPhonesStateStream.listen((event) {
      if (event == 'HEADPHONES_UNPLUGGED') {
        if (AudioService.playbackState.playing) {
          AudioService.pause();
        }
      }
    });

但是我收到了错误：

MissingPluginException(No implementation found for method listen on channel com.radioanime24.dev/headphones)

我应该如何注册eventchannel来忽略这个错误？

Answer 1

我认为您应该重写onCreate(savedInstanceState: Bundle?)方法，而不是Activity的onCreate(savedInstanceState: Bundle?, persistentState: PersistableBundle?)。