public string AlterItemInfo(int itemId     = 0, string itemName = "", string image    = "", string description = "", double price = 0, int categoryId = 0,
                                    int clickCount = 0, int stock       = 0, DateTime dateAdd = default, double cost   = 0, int sold      = 0, int discount   = 0)
        {
            Response response = new Response();

            response.status = false;
            //判断用户权限
            int  nowUserId  = Convert.ToInt32(HttpContext.Session.GetInt32("id"));
            bool nowIsadmin = Convert.ToBoolean(HttpContext.Session.GetString("admin"));

            if (nowUserId != 0 && nowIsadmin)
            {
                if (itemId != 0 && !Tool.IsNullOrEmpty(itemName, image, description))
                {
                    Item item = new Item();
                    item.Item_ID      = itemId;
                    item.Item_Name    = itemName;
                    item.Image_Url    = image;
                    item.Description  = description;
                    item.Item_Price   = price;
                    item.Category_ID  = categoryId;
                    item.Click_Counts = clickCount;
                    item.Stock        = stock;
                    item.Date_added   = dateAdd;
                    item.Cost         = cost;
                    item.Sold         = sold;
                    item.Discount     = discount;

                    bool result = ItemManager.AlterItemInfo(item);
                    if (result)
                    {
                        response.status  = true;
                        response.message = "修改成功";
                    }
                    else
                    {
                        response.message = "修改失败,请联系管理员";
                    }
                }
                else
                {
                    response.message = "修改失败,请检查资料是否填写完整";
                }
            }
            else
            {
                response.message = "没有权限";
            }
            return(JsonConvert.SerializeObject(response));
        }