这个事件不是点击键盘自动触发的事件吗？点了键盘在日志logcat里面没输出啊

//键盘事件
public boolean onKeyDown(int keyCode, KeyEvent event) {
int a=keyCode;
Log.i("GameView", ((Integer)a).toString());
//处理键盘事件
switch(keyCode){
case KeyEvent.KEYCODE_DPAD_UP:
player.move(Player.UP);
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
player.move(Player.DOWN);
break;
case KeyEvent.KEYCODE_DPAD_LEFT:
player.move(Player.LEFT);
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
player.move(Player.RIGHT);
break;
case KeyEvent.KEYCODE_DPAD_CENTER:
for (int i = 0; i < bullets.length; i++) {
if(bullets[i].getAlive()==false){
bullets[i].setAlive(true,player.getRefPixelX()-bullets[i].getWidth()/2,player.getRefPixelY()-player.getHeight());
break;
}
}
break;
}
return super.onKeyDown(keyCode, event);
}