使用MediaPlayer和AudioManager时，耳机和扬声器电话之间的切换不起作用

Question

我使用MediaPlayer通过< code>AsyncTask播放音频，并使用< code>AudioManager设置流。按下特定按钮时，我调用< code>AudioManager的< code>setSpeakerPhoneOn()进行切换，但它不会切换到耳机扬声器。我的音频总是通过主扬声器播放。

我尝试了这些解决方案(如下面的代码所示)，但都不起作用:

1. 按下按钮即可在听筒和免提电话之间切换
2. 音频管理器扬声器无法正常工作

以下是我在onViewCreated中初始化音频管理器的代码：

try {
            audioManager = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
            audioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);
            audioManager.setSpeakerphoneOn(loudOn);
            // loudOn is defined globally, and initialized to false
        }

这是使用AsyncTask的音频播放功能：

static private void playCall(final Context context, final String[] contactParts)
    {
        final MediaPlayer mediaPlayer = new MediaPlayer();
        new AsyncTask<Void,Void,Boolean>() {
            @Override
            protected Boolean doInBackground(Void... voids) {
                try {

                    mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                        @Override
                        public void onPrepared(MediaPlayer mp) {
                            mp.start();
                        }
                    });

                    mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                        @Override
                        public void onCompletion(MediaPlayer mp) {
                            mp.reset();
                            mp.release();
                        }
                    });

                    int audioFile_R_id = //get audio file id
                    try {
                        AssetFileDescriptor afd = context.getResources().openRawResourceFd(audioFile_R_id);
                        if (afd == null) return false;
                        mediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
                        afd.close();

                        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                            mediaPlayer.setAudioAttributes(new AudioAttributes.Builder()
                                    .setUsage(AudioAttributes.USAGE_VOICE_COMMUNICATION)
                                    .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
                                    .build());

                        } else {
                            //deprecated in API 26
                            mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
                        }

                        mediaPlayer.prepare();
                        return true;
                    }
                    catch (Resources.NotFoundException rnf)
                    {
                        rnf.printStackTrace();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return false;
            }

            @Override
            protected void onPostExecute(Boolean prepared) {
                if (prepared) {
                    mediaPlayer.start();
                }
            }
        }.execute();
    }

这是尝试切换的按钮代码：

loudFAB.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                loudOn = !loudOn;
                audioManager.setSpeakerphoneOn(loudOn);
            }
        });




Answer 1

更换音频管理器

    try {
            audioManager = (AudioManager) getContext().getSystemService(Context.AUDIO_SERVICE);
            audioManager.setMode(AudioManager.MODE_IN_CALL);
            audioManager.setSpeakerphoneOn(loudOn);
            // loudOn is defined globally, and initialized to false
        }