我使用此链接中的代码MediaSession onMediaButtonEvent 工作了几秒钟然后退出 - Android捕获远程按钮的键事件并将其发送到 audio() 函数，其中选择将由另一个媒体播放器播放。
我遇到了同样的问题，几秒钟后代码就会崩溃。到目前为止，我试图做一个循环，并使音轨不做 at.stop() 或做 at.release 但最终它仍然崩溃。这会使服务保持活动状态，但随后仍会崩溃。我有代码和 logcat
public class PlayerService extends Service {
private MediaSessionCompat mediaSession;
AudioTrack at;
@Override
public void onCreate() {
super.onCreate();
MediaSession ms = new MediaSession(getApplicationContext(), getPackageName());
ms.setActive(true);
ms.setCallback(new MediaSession.Callback() {
@Override
public boolean onMediaButtonEvent(Intent mediaButtonIntent) {
KeyEvent keyEvent = (KeyEvent) mediaButtonIntent.getExtras().get(Intent.EXTRA_KEY_EVENT);
if (keyEvent.getAction() == KeyEvent.ACTION_DOWN) {
switch (keyEvent.getKeyCode()) {
case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD:
audio("button0");
break;
case KeyEvent.KEYCODE_MEDIA_REWIND:
audio("button1");
break;
case KeyEvent.KEYCODE_MEDIA_NEXT:
audio("button2");
break;
case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
audio("button3");
break;
}
}
return super.onMediaButtonEvent(mediaButtonIntent);
}
});
Intent mediaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);
PendingIntent mediaButtonReceiverPendingIntent = PendingIntent.getBroadcast(getApplicationContext(), 0, mediaButtonIntent, 0);
ms.setMediaButtonReceiver(mediaButtonReceiverPendingIntent);
at = new AudioTrack(AudioManager.STREAM_MUSIC, 48000, AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT,
AudioTrack.getMinBufferSize(48000, AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT), AudioTrack.MODE_STREAM);
**//at.setLoopPoints(3, 10,10000000);
at.play();
at.stop();
at.release();**
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onDestroy() {
super.onDestroy();
mediaSession.release();
}
public void audio(String command) {
MediaPlayer player = new MediaPlayer();
try {
switch (command) {
case "button0":
player = MediaPlayer.create(this, R.raw.button0);
break;
case "button1":
player = MediaPlayer.create(this, R.raw.button1);
break;
case "button2":
player = MediaPlayer.create(this, R.raw.button2);
break;
case "button3":
player = MediaPlayer.create(this, R.raw.button3);
break;
}
player.start();
Thread.sleep(1000);
} catch (Exception e) {
e.printStackTrace();
}
}
}
我的 logcat 日志
2022-02-13 19:08:01.568 19045-19060/com.example.medialistenercopy W/MediaPlayer-JNI: MediaPlayer finalized without being released
2022-02-13 19:08:01.568 19045-19060/com.example.medialistenercopy I/MediaPlayerNative: setListener
2022-02-13 19:08:01.569 19045-19060/com.example.medialistenercopy I/MediaPlayerNative: disconnect
2022-02-13 19:08:01.580 19045-19060/com.example.medialistenercopy I/MediaPlayerNative: destructor
2022-02-13 19:08:01.581 19045-19060/com.example.medialistenercopy I/MediaPlayerNative: disconnect
2022-02-13 19:08:56.467 19045-19045/com.example.medialistenercopy D/AndroidRuntime: Shutting down VM
--------- beginning of crash
2022-02-13 18:57:56.595 17903-17903/com.example.medialistenercopy E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.medialistenercopy, PID: 17903
java.lang.RuntimeException: Unable to stop service com.example.medialistenercopy.PlayerService@e1c144e: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.media.session.MediaSessionCompat.release()' on a null object reference
at android.app.ActivityThread.handleStopService(ActivityThread.java:3880)
at android.app.ActivityThread.access$1700(ActivityThread.java:208)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1733)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:205)
at android.app.ActivityThread.main(ActivityThread.java:6991)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:884)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.media.session.MediaSessionCompat.release()' on a null object reference
at com.example.medialistenercopy.PlayerService.onDestroy(PlayerService.java:114)
at android.app.ActivityThread.handleStopService(ActivityThread.java:3860)
at android.app.ActivityThread.access$1700(ActivityThread.java:208)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1733)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:205)
at android.app.ActivityThread.main(ActivityThread.java:6991)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:884)
2022-02-13 18:57:56.668 17903-17903/com.example.medialistenercopy I/Process: Sending signal. PID: 17903 SIG: 9
问题是因为假音轨结束得太快还是因为我还有另一个媒体播放器也在播放声音。我正在尽我所能。
我试着调整音轨，我得到了
2022-02-13 20:58:55.609 27560-27560/com.example.medialistenercopy V/AudioTrack: getMinFrameCount=3844: afFrameCount=1920, afSampleRate=48000, afLatency=80
2022-02-13 20:58:55.610 27560-27560/com.example.medialistenercopy V/AudioTrack: set(): streamType -1, sampleRate 48000, format 0x1, channelMask 0x3, frameCount 3844, flags #0, notificationFrames 0, sessionId 0, transferType 3, uid -1, pid -1
2022-02-13 20:58:55.610 27560-27560/com.example.medialistenercopy V/AudioTrack: Building AudioTrack with attributes: usage=1 content=2 flags=0x0 tags=[]
2022-02-13 20:58:55.619 27560-27560/com.example.medialistenercopy W/AudioTrack: Use of stream types is deprecated for operations other than volume control
2022-02-13 20:58:55.619 27560-27560/com.example.medialistenercopy W/AudioTrack: See the documentation of AudioTrack() for what to use instead with android.media.AudioAttributes to qualify your playback use case
2022-02-13 20:58:55.625 27560-27560/com.example.medialistenercopy V/AudioTrack: ~AudioTrack, releasing session id 8857 from 27560 on behalf of 27560
2022-02-13 20:58:55.626 27560-27560/com.example.medialistenercopy W/MediaAnalyticsItem: Unable to record: [1:audiotrack:0:-1::0:-1:1:0:5:android.media.audiotrack.underrunframes=1922:android.media.audiotrack.type=AUDIO_CONTENT_TYPE_MUSIC:android.media.audiotrack.usage=AUDIO_USAGE_MEDIA:android.media.audiotrack.samplerate=48000:android.media.audiotrack.channelmask=3:] [forcenew=0]