2012年4月24日星期二

System.Web.Caching.Cache删除某键后,希望同时触发其它动作(关键时刻,还是事件靠的住)

System.Web.Caching.Cache删除某键后,希望同时触发其它动作(关键时刻,还是事件靠的住)

System.Web.Caching.Cache是.net为我们提供的一个轻量级的缓存组件,它提供了最基础的增,增过期,删除,获取等操作,下面是对Cache进行的一个封装,方便以后统一调用和扩展。

/// <summary>    /// 缓o存?相à关?的?操ù作÷类à    /// 占?占?    /// </summary>    public class DataCache    {        /// <summary>        /// 获?取?当±前°应|用?程ì序ò指?定¨CacheKey的?Cache值μ        /// </summary>        /// <param name="CacheKey"></param>        /// <returns></returns>        public static object GetCache(string CacheKey)        {            System.Web.Caching.Cache objCache = HttpRuntime.Cache;            return objCache[CacheKey];        }        /// <summary>        /// 设è置?当±前°应|用?程ì序ò指?定¨CacheKey的?Cache值μ        /// 调÷用?:oDataCache.SetCache("name", "zzl");        /// </summary>        /// <param name="CacheKey"></param>        /// <param name="objObject"></param>        public static void SetCache(string CacheKey, object objObject)        {            System.Web.Caching.Cache objCache = HttpRuntime.Cache;            objCache.Insert(CacheKey, objObject);        }        /// <summary>        /// 设è置?当±前°应|用?程ì序ò指?定¨CacheKey的?Cache值μ        /// 调÷用?:oDataCache.SetCache("name", "zzl", DateTime.Now.AddMinutes(1), TimeSpan.Zero);        /// </summary>        /// <param name="CacheKey"></param>        /// <param name="objObject"></param>        public static void SetCache(string CacheKey, object objObject, DateTime absoluteExpiration, TimeSpan slidingExpiration)        {            System.Web.Caching.Cache objCache = HttpRuntime.Cache;            objCache.Insert(CacheKey, objObject, null, absoluteExpiration, slidingExpiration);        }        /// <summary>        /// 移?除y指?定¨Cache        /// </summary>        /// <param name="CacheKey"></param>        public static void RemoveCache(string CacheKey)        {            System.Web.Caching.Cache objCache = HttpRuntime.Cache;            objCache.Remove(CacheKey);        }        #region Events        /// <summary>        /// 缓o存?删?除y事?件t        /// </summary>        public static event CacheEventHandler CacheDeleted;        #endregion        #region Methods        /// <summary>        /// 触¥发¢缓o存?删?除y事?件t        /// </summary>        public static void OnCacheDeleted(string key)        {            if ((CacheDeleted != null))            {                CacheDeleted(null, new CacheEventArgs(key));            }           Remove(key);        }        #endregion    }    #region Delegates    /// <summary>    /// 缓o存?委ˉ托D    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    public delegate void CacheEventHandler(object sender, CacheEventArgs e);    #endregion    /// <summary>    /// 缓o存?事?件t源′    /// </summary>    public class CacheEventArgs    {        public CacheEventArgs()        {        }        public CacheEventArgs(string cacheKey)        {            this.CacheKey = cacheKey;        }        public string CacheKey { get; set; }    }

在这个类中,有一个关于删除键时的事件,它的作用是在删除某个键时,进行与它关联的其它操作,例如:在用户登出时,希望将它的cache记录清除,并删除一些记录性的操作,但记录性的操作是不固定的,为了为破坏程序的完整性,我们可以在登出时,先去将其需要的操作进行有订阅,如果以后有其它删除cache键需要的关联操作,只要订阅就可以了

代码如下:

static CommonMethod()       {           iUserRepository = new UserRepository();           //订?阅?了?CacheDeleted这a个?事?件t,?当±它ü被?触¥发¢时±,?将?自?动ˉ执′行D被?绑ó定¨的?方?法¨           DataCache.CacheDeleted += new CacheEventHandler(ClearUserRecord);           DataCache.CacheDeleted += new CacheEventHandler(ClearProductRecord);       }
    #region 删?除yCache后ó,?需è要a做?的?其?它ü事?情é        static void ClearUserRecord(object sender, CacheEventArgs e)        {            DataCache.SetCache("msg1", e.CacheKey + "被?删?除y了?");        }        static void ClearProductRecord(object sender, CacheEventArgs e)        {            DataCache.SetCache("msg2", e.CacheKey + "真?的?被?删?除y了?");        }        #endregion

在登出操作后,可以去触发删除cache键的操作:

 

public static ActionResult UserLogOutModule(Controller controller)       {           string returnUrl = controller.Request.QueryString["returnUrl"];           Standard.ClientHelper.UserLogout();          DataCache.OnCacheDeleted("name");

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