Exoplayer 不会将当前位置从服务返回到活动？答案

【问题标题】：Exoplyaer won't return current position from service to activity?Exoplayer 不会将当前位置从服务返回到活动？
【发布时间】：2020-10-22 14:28:15
【问题描述】：

我的service 班级中有Exoplayer。我想将exoplayer 当前位置从service 发送到activity。我创建了一个broadcast receiver 用于交流。这是我的活动类中的广播接收器代码

class LocalAudioPlayer : AppCompatActivity() { 

inner class LocalAudioReceiver: BroadcastReceiver() {
        override fun onReceive(p0: Context?, intent: Intent?) {
            Log.i("here","here34")
            intent?.getStringExtra("message")?.let { Log.i("heythere", it) }
        }

    }



override fun onStart() {
        super.onStart()
        registerReceiver()
    }

    override fun onStop() {
        unregisterReceiver(localAudioReceiver)
        super.onStop()
    }

    private fun registerReceiver() {
        localAudioReceiver = LocalAudioReceiver()
        val intentFilter = IntentFilter()
        intentFilter.addAction(SENDMESAGGE)
        registerReceiver(localAudioReceiver, intentFilter)
    } ..

以下是我尝试将数据从服务发送回活动的方式

第一种方式我在onStartCommand的服务中写了以下代码

layer?.addListener(object : Player.EventListener {
            override fun onPlayerStateChanged(playWhenReady: Boolean, playbackState: Int) {
                when (playbackState) {
                    Player.STATE_ENDED -> {
                        //                    showControls();
                        //                    Toast.makeText(getApplicationContext(), "Playback ended", Toast.LENGTH_LONG).show();
                    }
                    Player.STATE_BUFFERING -> {
                        Log.i("heyyy","nnnnn")
                        passMessageToActivity(player?.currentPosition.toString())
                        Handler(Looper.getMainLooper()).postDelayed({
                            Log.i("hey123", "here123")
                            passMessageToActivity(player?.currentPosition.toString())
                        }, 0)
                        //                    progressBar.setVisibility(View.VISIBLE);
                        //                    Toast.makeText(getApplicationContext(), "Buffering..", Toast.LENGTH_SHORT).show();
                    }
                    Player.STATE_READY -> {
                        //                    progressBar.setVisibility(View.INVISIBLE);
                    }
                    Player.STATE_IDLE -> {

                    }
                }
            }
        })

第二种方法我尝试将上述代码从onStartCommand 移动到onCreate，但它不起作用

第三条路

尝试在 onCreate 中添加上述代码，但不起作用

 Handler(Looper.getMainLooper()).postDelayed({
        Log.i("hey123","here123")
        passMessageToActivity(player?.currentPosition.toString())
    }, 0)

第四条路

Runnable {
            passMessageToActivity(player?.currentPosition.toString())
        }

我在服务的onBind 中返回 null。这是造成问题吗？我想不断地将 exoplayer 当前位置从服务发送到活动

【问题讨论】：

标签： android kotlin android-activity broadcastreceiver android-service

【解决方案1】：

如果您正在寻找与Service 类中的Activity 交流的方法，请使用LocalBroadcastManager。

在Activity内部，创建广播接收器并注册

private val playerStateChangedReceiver = object : BroadcastReceiver() {
    override fun onReceive(context: Context?, intent: Intent?) {
        if (intent?.action == "player_state_changed") {
            val currentPosition = intent.getIntExtra("current_position", 0)
            toast("Current position: $currentPosition")
        }
    }
}

 override fun onStart() {
    super.onStart()
    LocalBroadcastManager.getInstance(context)
        .registerReceiver(playerStateChangedReceiver, IntentFilter("player_state_changed"))
}

override fun onStop() {
    super.onStop()
    LocalBroadcastManager.getInstance(context)
        .unregisterReceiver(playerStateChangedReceiver)
}

从Service 发送广播

LocalBroadcastManager.getInstance(context)
                .sendBroadcast(Intent("player_state_changed").apply {
                    putExtra("current_position", adapterPosition)
                })

【讨论】：