因为按键按下，会有DOWN 和UP 两种状态~哈哈

void handleUserEvents(ExMessage* msg,Snake *snake,Food *food) {
    //ExMessage msg;
    Direction dir = snake->direction;
    while (peekmessage(msg, EX_KEY,true)) {
        std::cout << "PeekMessageA" << std::endl;

        if (msg->message == WM_KEYDOWN) {
            std::cout << "WM_KEYDOWN" << std::endl;
        }