复杂业务简单化的一个小技巧

/// <summary>
    /// 数据配置类
    /// </summary>
    public class SmartConfig : BaseEntity
    {
        /// <summary>
        /// 类型
        /// </summary>
        [MaxLength(32)]
        public string Type { get; set; }
        /// <summary>
        /// 类型标识
        /// </summary>
        [MaxLength(32)]
        public string TypeIdentity { get; set; }
        /// <summary>
        /// 时间截
        /// </summary>
        [MaxLength(32)]
        public string Timestamp { get; set; }
        /// <summary>
        /// 配置
        /// </summary>
        public string Config { get; set; }
    }

 /// <summary>
    /// 业务数据配置类
    /// 请勿直接new这个对象，使用SmartConfigService.Get 方法获取对象
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <remarks>2014-08-20 ywb 创建</remarks>
    public class Smart<T>
    {
        /// <summary>
        /// 请勿直接new这个对象，使用SmartConfigService.Get 方法获取对象
        /// </summary>
        /// <param name="typeIdentity"></param>
        /// <param name="timestamp"></param>
        /// <param name="config"></param>
        public Smart(string typeIdentity, string timestamp, T config)
        {
            this.Timestamp = timestamp;
            this.Type = typeof(T).Name.Replace("C_", "");
            this.TypeIdentify = typeIdentity;
            this.Config = config;
        }
        /// <summary>
        /// 业务数据类型
        /// </summary>
        public string Type { get; private set; }
        /// <summary>
        /// 业务数据标识
        /// </summary>
        public string TypeIdentify { get; private set; }
        /// <summary>
        /// 时间戳
        /// </summary>
        public string Timestamp { get; private set; }
        /// <summary>
        /// 配置
        /// </summary>
        public T Config { get; private set; }
    }

/// <summary>
    /// 菜 配置
    /// </summary>
    /// <remarks>
    /// 约定命名规则为 前缀“C_ ”+ “业务表名”
    /// 这种方式不太符合规范但是好用，配合VS智能提示写代码方便    
    /// </remarks>
    public class C_Dish
    {
        public C_Dish()
        {
            //在构造函数中设置配置项的默认值
            NeedCooking = true;
            EnabledPrint = true;
            Return = false;
            AllowToCart = true;
        }
        /// <summary>
        /// 需要厨师烹饪
        /// </summary>
        [Description("需要厨师烹饪")]
        public bool NeedCooking { get; set; }
        /// <summary>
        /// 状态为“完成”时可退
        /// </summary>
        [Description("状态“完成”时能退")]
        public bool Return { get; set; }

        /// <summary>
        /// 启用打印
        /// </summary>
        [Description("启用打印")]
        public bool EnabledPrint { get; set; }

        /// <summary>
        /// 允许顾客点餐
        /// </summary>
        [Description("允许顾客点餐")]
        public bool AllowToCart { get; set; }
        

    }

/// <summary>
    /// 配置Service
    /// </summary>
    public static class SmartConfigService
    {
        /// <summary>
        /// 更新 SySmartConfig
        /// 如果返回false 很可能是并发引起的，需要业务终止执行。
        /// </summary>
        /// <param name="type">业务类型</param>
        /// <param name="typeIdentity">业务类型标识</param>
        /// <param name="config">配置</param>
        /// <param name="timestamp">更新前的时间戳</param>
        /// <param name="newTimestamp">更新后的时间戳</param>
        /// <returns></returns>
        public static bool Update(string type, string typeIdentity, string config, string timestamp, string newTimestamp)
        {
            
            var flag = DB.Wdd.Database.ExecuteSqlCommand("update SmartConfigs set Config={0},Timestamp={1} where Type={2} and TypeIdentity={3} and Timestamp={4}"
                , config, newTimestamp, type, typeIdentity, timestamp) == 1;
            CacheMemory.Remove(string.Format(CacheKey.Domain_SmartConfig, type, typeIdentity));
            return flag;

        }
        /// <summary>
        /// 获取 SySmartConfig 如果数据库中没有，则创建并返回SySmartConfig
        /// </summary>
        /// <param name="type">业务类型</param>
        /// <param name="typeIdentity">业务类型标识</param>
        /// <param name="timestamp">时间戳</param>
        /// <returns></returns>
        public static SmartConfig Get(string type, string typeIdentity, string timestamp)
        {
            var cacheKey = string.Format(CacheKey.Domain_SmartConfig, type, typeIdentity);
            return CacheMemory.Get<SmartConfig>(cacheKey, () =>
            {
                var config = DB.Wdd.SmartConfigs.FirstOrDefault(p => p.Type == type && p.TypeIdentity == typeIdentity);
                if (config != null) return config;

                config = new SmartConfig()
                {
                    Config = string.Empty,
                    Timestamp = timestamp,
                    Type = type,
                    TypeIdentity = typeIdentity
                };
                DB.Wdd.AddEntity<SmartConfig>(config);
                return config;
            }, new TimeSpan(24, 0, 0));
        }

        /// <summary>
        /// 保存 业务数据配置
        /// 如果返回false 很可能是并发引起的，需要业务终止执行。
        /// </summary>
        /// <param name="smart">业务数据配置.</param>
        public static bool Save<T>(Smart<T> smart)
        {
            if (smart == null) throw new ArgumentNullException("smart");
            return Update(smart.Type, smart.TypeIdentify, Newtonsoft.Json.JsonConvert.SerializeObject(smart.Config), smart.Timestamp, Timestamp(DateTime.Now));
        }

        /// <summary>
        /// 获取 业务数据配置
        /// </summary>
        /// <param name="typeIdentity">业务类型标识.</param>
        public static Smart<T> Get<T>(string typeIdentity)
        {
            var type = typeof(T).Name.Replace("C_", "");
            var smartConfig = Get(type, typeIdentity, Timestamp(DateTime.Now));
            if (string.IsNullOrEmpty(smartConfig.Config)) smartConfig.Config = "{}";

            //转换出错异常不处理
            var config = Newtonsoft.Json.JsonConvert.DeserializeObject<T>(smartConfig.Config);
            return new Smart<T>(typeIdentity, smartConfig.Timestamp, config);
        }

        /// <summary>
        /// 获取时间戳.
        /// </summary>
        /// <param name="dt">时间.</param>
        /// <returns></returns>
        private static string Timestamp(DateTime dt)
        {
            DateTime dt1 = new DateTime(1970, 1, 1);
            TimeSpan ts = dt - dt1;
            return ts.TotalMilliseconds.ToString();
        }
    }