点餐系统，实现用户登录，菜单浏览，菜单详细信息查看，将餐品放入购物车，修改购物车，清空清空购物车，下订单等功能。-Ordering system, to achieve user login, browse the menu, the menu for more information see, the food product into the shopping cart, modify the shopping cart, empty the empty shopping cart, ord