通过插上耳机的扬声器播放音频

Question

我想用插入式耳机通过扬声器播放音频文件。

AudioManager audioManager = (AudioManager)mainActivity
     .getSystemService(Context.AUDIO_SERVICE);
audioManager.setMode(AudioManager.STREAM_MUSIC);
audioManager.setSpeakerphoneOn(true);
MediaPlayer mp = MediaPlayer.create(mainActivity, R.raw.chime);
mp.setAudioStreamType(AudioManager.STREAM_RING);
mp.start();

<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />

   MediaPlayer mp = MediaPlayer.create(mainActivity, R.raw.chime);
   AudioManager am = (AudioManager) mainActivity.getSystemService(mainActivity.AUDIO_SERVICE);
    try {
        mp.setAudioStreamType(AudioManager.STREAM_ALARM);
        mp.setLooping(true);
        mp.prepare();
    } catch (IllegalArgumentException | SecurityException| IllegalStateException | IOException e) {
        Log.i("TAG","Error is " + e.toString());
        e.printStackTrace();
    }
    am.requestAudioFocus(null, AudioManager.STREAM_ALARM,AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);
    mp.start();

但我得到了

IllegalStateException

有什么想法可以解决这个问题吗？

Answer 1

我将提供一个完整的代码片段（在Android24上测试），我必须将其从多个提示聚合到解决方案：

public class AudioClass
{
    AudioManager audioManager;
    Activity activity;

    public AudioClass(Activity activity)
    {
       this.activity = activity;

        //NEEDS TO BE DONE BEFORE PLAYING AUDIO!
        audioManager = (AudioManager)
            activity.getSystemService(Context.AUDIO_SERVICE);
        audioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);
        audioManager.setSpeakerphoneOn(true);
    }

    public void playAudio() {
        //CAN BE CALLED FROM ANYWHERE AFTER AudioClass IS INSTANTIATED
        MediaPlayer mp = MediaPlayer.create(activity, R.raw.audio_file_name);
        mp.setAudioStreamType(AudioManager.MODE_IN_COMMUNICATION);
        mp.start();
    }
}

并且修改音频设置的权限需要在清单中设置：

<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />