interface ICache

    {

        /// <summary>

        /// 添加

        /// </summary>

        /// <param name="key"></param>

        /// <param name="value"></param>

        /// <param name="expiratTime"></param>

        void Add(string key, object value, int expiratTime = 30);

        /// <summary>

        /// 获取

        /// </summary>

        /// <typeparam name="T"></typeparam>

        /// <param name="key"></param>

        /// <returns></returns>

        T Get<T>(string key);

        /// <summary>

        /// 是否包含

        /// </summary>

        /// <param name="key"></param>

        /// <returns></returns>

        bool Contains(string key);

        /// <summary>

        /// 删除指定key

        /// </summary>

        /// <param name="key"></param>

        void Remove(string key);

        /// <summary>

        /// 删除所有

        /// </summary>

        void RemoveAll();

        /// <summary>

        /// 索引访问器

        /// </summary>

        /// <param name="key"></param>

        /// <returns></returns>

        object this[string key] { get; set; }

        /// <summary>

        /// 数量

        /// </summary>

        int Count { get; }

    }

 public class CustomerCache : ICache

    {

        private static Dictionary<string, KeyValuePair<object, DateTime>> _dictionary = new Dictionary<string, KeyValuePair<object, DateTime>>();

        static CustomerCache()

        {

            new Action(() =>

            {

                while (true)

                {

                    Thread.Sleep(100);

                    foreach (var item in _dictionary.Where(t => t.Value.Value < DateTime.Now))

                    {

                        _dictionary.Remove(item.Key);

                    }

                }

            }).BeginInvoke(null, null);

        }

        public void  Add(string key, object value, int expiratTime = 30)

        {

            KeyValuePair<object, DateTime> keyValue = new KeyValuePair<object, DateTime>(value, DateTime.Now.AddMinutes(expiratTime));

            _dictionary[key] = keyValue;

        }

        public bool Contains(string key)

        {

            if (_dictionary.ContainsKey(key))

            {

                KeyValuePair<object, DateTime> keyValue = _dictionary[key];

                if (keyValue.Value > DateTime.Now)//没有过期

                {

                    return true;

                }

                else

                {

                    _dictionary.Remove(key);//过期清除

                    return false;

                }

            }

            return false;

        }

        public T Get<T>(string key)

        {

            if (_dictionary.ContainsKey(key))

            {

                KeyValuePair<object, DateTime> keyValue = _dictionary[key];

                if (keyValue.Value > DateTime.Now)//没有过期

                {

                    return (T)keyValue.Key;

                }

                else

                {

                    _dictionary.Remove(key);//过期清除

                    return default(T);

                }

            }

            return default(T);

        }

        public void Remove(string key)

        {

             _dictionary.Remove(key);

        }

        public void RemoveAll()

        {

            _dictionary = new Dictionary<string, KeyValuePair<object, DateTime>>();

        }

        public object this[string key]

        {

            get

            {

                return this.Get<object>(key);

            }

            set

            {

                this.Add(key, value);

            }

        }

        public int Count

        {

            get

            {

                return _dictionary.Values.Where(t => t.Value > DateTime.Now).Count();

            }

        }

    }

public class CacheManager

    {

        private CacheManager()

        {

        }

        private static ICache cache = null;

        static CacheManager()

        {

            cache = (ICache)Activator.CreateInstance(typeof(CustomerCache));

        }

        #region ICache

        public static int Count

        {

            get { return cache.Count; }

        }

        public static bool Contains(string key)

        {

            return cache.Contains(key);

        }

        public static T Get<T>(string key)

        {

            return cache.Get<T>(key);

        }

        public static void Add(string key, object value, int expiratTime = 30)

        {

            if (Contains(key))

                cache.Remove(key);

            cache.Add(key, value, expiratTime);

        }

        /// <summary>

        /// 删除缓存数据项

        /// </summary>

        /// <param name="key"></param>

        public static void Remove(string key)

        {

            cache.Remove(key);

        }

        /// <summary>

        /// 删除所有缓存数据项

        /// </summary>

        public static void RemoveAll()

        {

            cache.RemoveAll();

        }

        #endregion

    }