public string AddAttrValue(string valueName, string attrid, string operateid)
        {
            var valueid = Guid.NewGuid().ToString().ToLower();
            var dal = new ProductsDAL();
            if (dal.AddAttrValue(valueid, valueName, attrid, operateid))
            {
                var model = GetAttrByID(attrid);
                model.AttrValues.Add(new AttrValue()
                {
                    ValueID = valueid,
                    ValueName = valueName,
                    Status = 1,
                    AttrID = attrid,
                    CreateTime = DateTime.Now
                });

                return valueid;
            }
            return string.Empty;
        }