onKeyDown事件每隔30-40毫秒就会被调用一次......为什么？

Question

我正在测试一个试图将物理键盘键绑定到它的游戏。我实现了onKeyUp和onKeyDown来知道用户何时按下了移动键。问题是onKeyDown事件每30-40ms被重复调用一次。

理论上，如果我在不执行onKeyUp的情况下按下按键，则必须只调用一次，但是在我执行keyUp之前它会被调用很多次。

有什么问题？这是代码：

        @Override
        public boolean onKeyDown(int keyCode, KeyEvent event) {
            int factor = GameState.getInstance().getSpaceship().getSpeedFactorCorrespondence();
            int movementRange = sh/factor;
            switch (keyCode) {
            case KeyEvent.KEYCODE_W:
                Log.d("XX_KEYBOARD","onKeyDown KEYCODE_W "+keyCode);
                GameState.getInstance().setJoyY(movementRange);
                return true;
            case KeyEvent.KEYCODE_A:
                Log.d("XX_KEYBOARD","onKeyDown KEYCODE_A "+keyCode);
                GameState.getInstance().setJoyX(-movementRange);
                return true;
            case KeyEvent.KEYCODE_S:
                Log.d("XX_KEYBOARD","onKeyDown KEYCODE_S "+keyCode);
                GameState.getInstance().setJoyY(-movementRange);
                return true;
            case KeyEvent.KEYCODE_D:
                Log.d("XX_KEYBOARD","onKeyDown KEYCODE_D "+keyCode);
                GameState.getInstance().setJoyX(movementRange);
                return true;
            case KeyEvent.KEYCODE_J:
                Log.d("XX_KEYBOARD","onKeyDown KEYCODE_J "+keyCode);
                touchX=sw/2;
                touchY=sh/2;
                LaserManager.getInstance().startLaserThread();
                return true;
            default:
                Log.d("XX_KEYBOARD","onKeyDown default "+keyCode);
                return super.onKeyDown(keyCode, event);
        }
    }