ASP.NET缓存处理

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Collections;using System.Web.Caching;using System.Text.RegularExpressions;namespace Maticsoft.Web.Common{    public class CacheUtil    {                #region 增加一个缓存对象        /// <summary>        /// 增加一个缓存对象        /// </summary>        /// <param name="strKey">键值名称</param>        /// <param name="valueObj">被缓存对象</param>        /// <param name="durationMin">缓存失效时间，默认为3分钟</param>        /// <param name="priority">保留优先级(枚举数值)，1最不会被清除，6最容易被内存管理清除,0为default        /// 【1:NotRemovable；2:High；3:AboveNormal；4:Normal；5:BelowNormal；6:Low】</param>        /// <returns>缓存写入是否成功true 、 false</returns>        public static bool InsertCach(string strKey, object valueObj, int durationMin, int priority)        {            TimeSpan ts;            if (strKey != null && strKey.Length != 0 && valueObj != null)            {                //建立回调委托的一个实例                //onRemove是委托执行的函数，具体方法看下面的onRemove(...)                CacheItemRemovedCallback callBack = new CacheItemRemovedCallback(onRemove);                #region 失效时间设置                if (durationMin == 0)                {                    ts = new TimeSpan(0, 3, 0);//如果不进行设置则为三分钟                }                else                {                    ts = new TimeSpan(0, durationMin, 0);                }                #endregion                #region System.Web.Caching.Cache 对象中存储的项的相对优先级                CacheItemPriority cachePriority;                switch (priority)                {                    case 6:                        cachePriority = CacheItemPriority.Low;                        break;                    case 5:                        cachePriority = CacheItemPriority.BelowNormal;                        break;                    case 4:                        cachePriority = CacheItemPriority.Normal;                        break;                    case 3:                        cachePriority = CacheItemPriority.AboveNormal;                        break;                    case 2:                        cachePriority = CacheItemPriority.High;                        break;                    case 1:                        cachePriority = CacheItemPriority.NotRemovable;                        break;                    default:                        cachePriority = CacheItemPriority.Default;                        break;                }                #endregion                HttpContext.Current.Cache.Insert(strKey, valueObj, null, DateTime.Now.Add(ts), System.Web.Caching.Cache.NoSlidingExpiration, cachePriority, callBack);                return true;            }            else            {                return false;            }        }        #endregion        #region 判断缓存对象是否存在        /// <summary>        /// 判断缓存对象是否存在        /// </summary>        /// <param name="strKey">缓存键值名称</param>        /// <returns>是否存在true 、false</returns>        public static bool IsExist(string strKey)        {            return HttpContext.Current.Cache[strKey] != null;        }        #endregion        #region 读取缓存对象        /// <summary>        /// 读取缓存对象        /// </summary>        /// <param name="strKey">缓存键值名称</param>        /// <returns>缓存对象，objec类型</returns>        public static object GetCache(string strKey)        {//取出值            if (HttpContext.Current.Cache[strKey] != null)            {                object obj = HttpContext.Current.Cache[strKey];                if (obj == null)                {                    return null;                }                else                {                    return obj;                }            }            else            {                return null;            }        }        #endregion        #region 删除缓存对象        /// <summary>        /// 删除缓存对象        /// </summary>        /// <param name="strKey">缓存键值名称</param>        public static void Remove(string strKey)        {            if (HttpContext.Current.Cache[strKey] != null)            {                HttpContext.Current.Cache.Remove(strKey);            }        }        #endregion        #region 根据设置的正则表达式清除缓存对象        /// <summary>        /// 根据设置的正则表达式清除缓存对象；        /// 该方法使用正则匹配要删除的键值对象，如果键值命名统一规范，可批处理清除相关缓存数据O(∩_∩)O        /// </summary>        /// <param name="pattern">匹配键值的正则表达式</param>        public static void RemoveByRegexp(string pattern)        {            if (pattern != "")            {                IDictionaryEnumerator enu = HttpContext.Current.Cache.GetEnumerator();                while (enu.MoveNext())                {                    string key = enu.Key.ToString();                    if (Regex.IsMatch(key, pattern))                    {                        Remove(key);                    }                }            }        }        #endregion        #region 清除所有缓存对象        /// <summary>        /// 清除所有缓存对象        /// </summary>        public static void Clear()        {            IDictionaryEnumerator enu = HttpContext.Current.Cache.GetEnumerator();            while (enu.MoveNext())            {                Remove(enu.Key.ToString());            }        }        #endregion        #region 此方法在值失效之前调用，可以用于在失效之前更新数据库，或从数据库重新获取数据        public static CacheItemRemovedReason reason;               /// <summary>        /// 此方法在值失效之前调用，可以用于在失效之前更新数据库，或从数据库重新获取数据        /// </summary>        /// <param name="strKey"></param>        /// <param name="obj"></param>        /// <param name="reason"></param>        private static void onRemove(string strKey, object obj, CacheItemRemovedReason r)        {            reason = r;        }        #endregion    }}