Cnic.CacheHelper<T>

    public class UserBLL
    {
        public class UserInfo
        {
            public int ID { get; set; }
            public string Email { get; set; }
            public string UserName { get; set; }
        }

        public UserInfo GetModel(int id)
        {
            return null;//dal.GetModel(id);
        }
        public UserInfo GetModelByCache(int id)
        {
            CacheHelper<UserInfo> cacheHelper = new CacheHelper<UserInfo>();
            cacheHelper.CacheTime = 10000;
            cacheHelper.CacheKey = "Model.UserInfo." + id;
            return cacheHelper.GetValue(id, new CacheHelper<UserInfo>.IntHandel(GetModel));
        }

        public UserInfo GetModel(string email)
        {
            return null;//dal.GetModel(email);
        }
        public UserInfo GetModelByCache(string email)
        {
            CacheHelper<UserInfo> cacheHelper = new CacheHelper<UserInfo>();
            cacheHelper.CacheTime = 10000;
            cacheHelper.CacheKey = "Model.UserInfo." + email;
            return cacheHelper.GetValue(email, new CacheHelper<UserInfo>.StringHandel(GetModel));
        }

        public int Update(UserInfo model)
        {
            int rtun = 0;//dal.Update(model);
            if (rtun > 0)
            {
                new CacheHelper<UserInfo>() { CacheKey= "Model.UserInfo." + model.Email }.Remove();
                new CacheHelper<UserInfo>() { CacheKey = "Model.UserInfo." + model.ID }.Remove();
            }
            return rtun;
        }
    }

    public class CacheHelper<T>
    {
        /// <summary>
        /// 多长时间没有访问后过期
        /// </summary>
        /// <param name="key"></param>
        /// <param name="value"></param>
        /// <param name="time"></param>
        public static void Insert(string key, object value, TimeSpan time)
        {
            if (value != null)
            {
                System.Web.HttpRuntime.Cache.Insert(
                   key,
                   value,
                   null,
                   System.Web.Caching.Cache.NoAbsoluteExpiration,
                   time);
            }
        }
        /// <summary>
        /// 指定时间过期
        /// </summary>
        /// <param name="key"></param>
        /// <param name="value"></param>
        /// <param name="time">DateTime.UtcNow.AddSeconds(10)</param>
        public static void Add(string key, object value, DateTime time)
        {
            if (value != null)
            {
                System.Web.HttpRuntime.Cache.Add(
                    key,
                    value,
                    null,
                    time,//10秒
                    System.Web.Caching.Cache.NoSlidingExpiration,
                    System.Web.Caching.CacheItemPriority.High,
                    null);
            }
        }

        public static object Remove(string key)
        {
            if (key == null) { return null; }
            return System.Web.HttpRuntime.Cache.Remove(key);
        }

        public class CacheObject
        {
            //public bool IsExist { get; set; }
            public T Value { get; set; }
        }

        public string CacheKey { get; set; }
        public int CacheTime { get; set; }
        public IntHandel CacheIntHandel { get; set; }
        public StringHandel CacheStringHandel { get; set; }

        public delegate T IntHandel(int id);
        public delegate T StringHandel(string key);


        public T GetValue(int id, IntHandel handel)
        {
            CacheObject rtun = System.Web.HttpRuntime.Cache[CacheKey] as CacheObject;
            if (rtun == null)
            {
                rtun = new CacheObject();
                rtun.Value = handel(id);
                //rtun.IsExist = rtun.Value != null;
                Insert(CacheKey, rtun, TimeSpan.FromSeconds(CacheTime));
            }
            return rtun.Value;
        }
        public T GetValue(string key, StringHandel handel)
        {
            CacheObject rtun = System.Web.HttpRuntime.Cache[CacheKey] as CacheObject;
            if (rtun == null)
            {
                rtun = new CacheObject();
                rtun.Value = handel(key);
                //rtun.IsExist = rtun.Value != null;
                Insert(CacheKey, rtun, TimeSpan.FromSeconds(CacheTime));
            }
            return rtun.Value;
        }
        public T Remove()
        {
            CacheObject rtun = System.Web.HttpRuntime.Cache[CacheKey] as CacheObject;
            if (rtun == null) { return default(T); }
            return rtun.Value;
        }
    }