如何在Android onMediaButtonEvent中收听“ ACTION_DOWN”（按键）事件，以测量时间？

我自己解决了这个问题。诀窍是使用

event.getDownTime()

    audioSession = new MediaSession(getApplicationContext(), "TAG");    audioSession.setCallback(new MediaSession.Callback() {    @Override    public boolean onMediaButtonEvent(final Intent mediaButtonIntent) {        String intentAction = mediaButtonIntent.getAction();        if (Intent.ACTION_MEDIA_BUTTON.equals(intentAction)) { KeyEvent event = mediaButtonIntent.getParcelableExtra(Intent.EXTRA_KEY_EVENT); if (event != null) {     stopTimeOfGame_millis = event.getDownTime();     double usersReactionTime = (event.getDownTime() - startTimeOfGame_millis) / 1000.0;     UtilsRG.info("event.getDownTime(): " + usersReactionTime);     double getEventTime = (event.getEventTime() - startTimeOfGame_millis) / 1000.0;     UtilsRG.info("event.getEventTime(): " + getEventTime);     int action = event.getAction();     if (action == KeyEvent.ACTION_DOWN) {         long action_down = android.os.SystemClock.uptimeMillis();         double actionDown = (action_down - startTimeOfGame_millis) / 1000.0;         UtilsRG.info("ACTION_DOWN: " + actionDown);     }     if (action == KeyEvent.ACTION_UP) {         long action_up = android.os.SystemClock.uptimeMillis();         double actionUp = (action_up - startTimeOfGame_millis) / 1000.0;         UtilsRG.info("ACTION_UP: " + actionUp);     } }        }        return true;    }    });    PlaybackState state = new PlaybackState.Builder() .setActions(PlaybackState.ACTION_PLAY_PAUSE) .setState(PlaybackState.STATE_PLAYING, 0, 0, 0) .build();    audioSession.setPlaybackState(state);    audioSession.setFlags(MediaSession.FLAG_HANDLES_MEDIA_BUTTONS | MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS);    audioSession.setActive(true);

我得到以下日志：

event.getDownTime（）：0.281

event.getEventTime（）：0.421

ACTION_DOWN：0.47

ACTION_UP：0.471

因此，现在我得到了用户按下按键的瞬间。

特别感谢Balkrishna Rawool