企业库5.0——缓存应用

using System;
 using Microsoft.Practices.EnterpriseLibrary.Caching;
 using Microsoft.Practices.EnterpriseLibrary.Caching.Expirations;namespace SpecialSale.Sys.SysCache
 {
   /// <summary>
   /// 缓存过期类型枚举
   /// </summary>
   public enum EnumCacheExpirationType
   {
     /// <summary>
     /// 绝对过期
     /// </summary>
     AbsoluteTime = 1,
     /// <summary>
     /// 固定过期
     /// </summary>
     SlidingTime = 2,
     /// <summary>
     /// 指定过期格式，以特定的格式来过期
     /// </summary>
     ExtendedFormatTime=3,
     /// <summary>
     /// 文件依赖
     /// </summary>
     FileDependency=4,
   }  public static class CacheHelper
   {
     //2种建立CacheManager的方式
     //ICacheManager cache = EnterpriseLibraryContainer.Current.GetInstance<ICacheManager>();
     private static ICacheManager cache = CacheFactory.GetCacheManager();    /// <summary>
     /// 添加缓存
     /// </summary>
     /// <param name="key">键</param>
     /// <param name="value">值</param>
     /// <param name="type">缓存过期类型</param>
     public static void Add(string key, object value, EnumCacheExpirationType type)
     {
       switch (type)
       {
         case EnumCacheExpirationType.AbsoluteTime:
           cache.Add(key, value, CacheItemPriority.Normal, new SysCacheItemRefreshAction(), new AbsoluteTime(TimeSpan.FromMinutes(15)));
           break;
         case EnumCacheExpirationType.SlidingTime: 
           cache.Add(key, value, CacheItemPriority.Normal, new SysCacheItemRefreshAction(), new SlidingTime(TimeSpan.FromMinutes(15)));
           break;
         case EnumCacheExpirationType.ExtendedFormatTime:
           throw new Exception("暂时不支持 ExtendedFormatTime 过期");
           break;
         case EnumCacheExpirationType.FileDependency:
           throw new Exception("暂时不支持 FileDependency 过期");
           break;
       }
     }    /// <summary>
     /// 获取缓存对象
     /// </summary>
     /// <param name="key">键</param>
     /// <returns></returns>
     public static T GetCache<T>(string key) where T:class 
     {
       return cache.GetData(key) as T;
     }    /// <summary>
     /// 移除缓存对象
     /// </summary>
     /// <param name="key">键</param>
     public static void RemoveCache(string key)
     {
       cache.Remove(key);
     }
   }  /// <summary>
   /// 自定义缓存刷新操作
   /// </summary>
   [Serializable]
   public class SysCacheItemRefreshAction : ICacheItemRefreshAction
   {
     #region ICacheItemRefreshAction 成员    /// <summary>
     /// 自定义刷新操作
     /// </summary>
     /// <param name="removedKey">移除的键</param>
     /// <param name="expiredValue">过期的值</param>
     /// <param name="removalReason">移除理由</param>
     void ICacheItemRefreshAction.Refresh(string removedKey, object expiredValue, CacheItemRemovedReason removalReason)
     {
       if (removalReason == CacheItemRemovedReason.Expired)
       {
         ICacheManager cache = CacheFactory.GetCacheManager();
         cache.Add(removedKey, expiredValue);
       }
     }
     #endregion
   }
 }