如果我在 Android 中以挂起乐趣启动 MediaRecorder.start() 并以正常乐趣启动 MediaRecorder.stop() 会导致错误吗？

Question

录制音频是一个长时间的操作，所以我mRecorder?.start()在一个服务内的一个协程中启动，你可以看到RecordService.kt。

我祈求suspend fun startRecord(){...}在AndroidViewModel与viewModelScope.launch { }开始录制音频。

我只调用一个正常的fun stopRecord(){...}inAndroidViewModel来停止录制音频，你可以看到HomeViewModel.kt，它会导致对象出错var mRecorder: MediaRecorder?吗？

HomeViewModel.kt

class HomeViewModel(val mApplication: Application, private val mDBVoiceRepository: DBVoiceRepository) : AndroidViewModel(mApplication) {

    private var mService: RecordService? = null

    private val serviceConnection = object : ServiceConnection {
        override fun onServiceConnected(className: ComponentName, iBinder: IBinder) {
            val binder = iBinder as RecordService.MyBinder
            mService = binder.service
        }
       ...
    }


    fun bindService() {
        Intent(mApplication , RecordService::class.java).also { intent ->
            mApplication.bindService(intent, serviceConnection, Context.BIND_AUTO_CREATE)
        }
    }  

    fun unbindService() {
        Intent(mApplication, RecordService::class.java).also { intent ->
            mApplication.unbindService(serviceConnection)
        }
    }

    fun startRecord(){
        viewModelScope.launch {
            mService?.startRecord()
        }
    }

    fun stopRecord(){
        mService?.stopRecord()
    }      
}

记录服务.kt

class RecordService : Service() {

    private var mRecorder: MediaRecorder? = null

    suspend fun startRecord(){

        mRecorder = MediaRecorder()

        withContext(Dispatchers.IO) {
            mRecorder?.setOutputFile(filename);

            mRecorder?.setMaxDuration(1000*60*20); //20 Mins
            mRecorder?.setAudioChannels(1);
            mRecorder?.setAudioSamplingRate(44100);
            mRecorder?.setAudioEncodingBitRate(192000);

            mRecorder?.prepare()
            mRecorder?.start()
        }
    }


    fun stopRecord(){
        mRecorder?.stop()
        mRecorder=null
    }

}

Answer 1

不，它不会导致错误，但如果您在调用此方法时遇到运行时错误，可能是由于录音机没有收到任何有效的声音或视频来录制。检查下面的文档链接以获取更多信息。

https://developer.android.com/reference/android/media/MediaRecorder#stop()