Asp.net-代码学习：DataCache

using System;
using System.Web;
using System.Web.Caching;
using System.Collections;

namespace WebApplication1
{
 /// <summary>
 /// 缓存的类型，他们之间是否是包含关系？
 /// </summary>
 public enum CoreCacheType
 {
  Host = 1,
  Portal,
  Tab
 }

 /// <summary>
 /// 对系统缓存的操作
 /// </summary>
 public class DataCache
 {
  public DataCache()
  {
   //
   // TODO: 在此处添加构造函数逻辑
   //
  }

  /// <summary>
  /// 取得某缓存的值
  /// </summary>
  /// <param name="CacheKey">缓存的键</param>
  /// <returns>缓存的值</returns>
  public static object GetCache(string CacheKey)
  {
   // HttpRuntime.Cache：获取当前应用程序的 System.Web.Caching.Cache。
   // System.Web.Caching.Cache：实现用于 Web 应用程序的缓存。
   Cache objCache = HttpRuntime.Cache;
   return objCache[CacheKey];
  }

  /// <summary>
  /// 设置某缓存的值。
  /// </summary>
  /// <param name="CacheKey">缓存的键</param>
  /// <param name="objObject">缓存的值</param>
  public static void SetCache(string CacheKey, object objObject)
  {
   Cache objCache = HttpRuntime.Cache;
   objCache.Insert(CacheKey, objObject);
  }

  /// <summary>
  /// 设置某缓存的值和跟踪缓存依赖项。
  /// </summary>
  /// <param name="CacheKey">缓存的键</param>
  /// <param name="objObject">缓存的值</param>
  /// <param name="objDependency">缓存依赖项</param>
  public static void SetCache(string CacheKey, object objObject, CacheDependency objDependency)
  {
   Cache objCache = HttpRuntime.Cache;
   objCache.Insert(CacheKey, objObject, objDependency);
  }

  /// <summary>
  /// 设置某缓存的值和跟踪缓存依赖项。
  /// </summary>
  /// <param name="CacheKey">缓存的键</param>
  /// <param name="objObject">缓存的值</param>
  /// <param name="objDependency">缓存依赖项</param>
  /// <param name="AbsoluteExpiration">缓存移出的时间</param>
  /// <param name="SlidingExpiration">缓存的有效期时间长度</param>
  public static void SetCache(string CacheKey, object objObject, CacheDependency objDependency, DateTime AbsoluteExpiration, TimeSpan SlidingExpiration)
  {
   Cache objCache = HttpRuntime.Cache;
   objCache.Insert(CacheKey, objObject, objDependency, AbsoluteExpiration, SlidingExpiration);
  }

  /// <summary>
  /// 设置某缓存的值。
  /// </summary>
  /// <param name="CacheKey">缓存的键</param>
  /// <param name="objObject">缓存的值</param>
  /// <param name="SlidingExpiration">缓存的有效期时间长度</param>
  public static void SetCache(string CacheKey, object objObject, TimeSpan SlidingExpiration)
  {
   Cache objCache = HttpRuntime.Cache;
   objCache.Insert(CacheKey, objObject, null, Cache.NoAbsoluteExpiration, SlidingExpiration);
  }

  /// <summary>
  ///  设置某缓存的值。
  /// </summary>
  /// <param name="CacheKey">缓存的键</param>
  /// <param name="objObject">缓存的值</param>
  /// <param name="AbsoluteExpiration">缓存移出的时间</param>
  public static void SetCache(string CacheKey, object objObject, DateTime AbsoluteExpiration)
  {
   Cache objCache = HttpRuntime.Cache;
   objCache.Insert(CacheKey, objObject, null, AbsoluteExpiration, Cache.NoSlidingExpiration);
  }

  /// <summary>
  /// 从缓存中移出某键的缓存值
  /// </summary>
  /// <param name="CacheKey">缓存的键</param>
  public static void RemoveCache(string CacheKey)
  {
   Cache objCache = HttpRuntime.Cache;
   if (objCache[CacheKey] != null)
   {
    objCache.Remove(CacheKey);
   }
  }

  public static void ClearCoreCache(CoreCacheType Type, int ID, bool Cascade)
  {
   switch (Type)
   {
     // 清除Host缓存
    case CoreCacheType.Host:
     ClearHostCache(Cascade);
     break;
     // 清除Portal缓存
    case CoreCacheType.Portal:
     ClearPortalCache(ID, Cascade);
     break;
     // 清除Tab缓存
    case CoreCacheType.Tab:
     ClearTabCache(ID);
     break;
    default:
     break;
   }
  }

  /// <summary>
  /// 清除Host缓存。
  /// </summary>
  /// <param name="Cascade"></param>
  private static void ClearHostCache(bool Cascade)
  {
   Cache objCache = HttpRuntime.Cache;

   if (objCache["GetHostSettings"] != null)
   {
    objCache.Remove("GetHostSettings");
   }

   if (objCache["GetPortalByAlias"] != null)
   {
    objCache.Remove("GetPortalByAlias");
   }

   if (objCache["CSS"] != null)
   {
    objCache.Remove("CSS");
   }

   if (Cascade)
   {
    PortalController objPortals = new PortalController();

    // 在这里声明PortalInfo，是为了提高效率考虑。
    PortalInfo objPortal;

    // 取得一个PortalInfo集合
    ArrayList arrPortals = objPortals.GetPortals();

    for (int intIndex = 0; intIndex < arrPortals.Count; intIndex++)
    {
     objPortal = (PortalInfo)arrPortals[intIndex];

     // 清除Portal缓存
     ClearPortalCache(objPortal.PortalID, Cascade);
    }
   }
  }

  /// <summary>
  /// 清除Portal缓存。
  /// </summary>
  /// <param name="PortalId"></param>
  /// <param name="Cascade"></param>
  private static void ClearPortalCache(int PortalId, bool Cascade)
  {
   Cache objCache = HttpRuntime.Cache;

   if (objCache["GetPortalSettings" + PortalId] != null)
   {
    objCache.Remove("GetPortalSettings" + PortalId);
   }

   if (objCache["GetTabs" + PortalId] != null)
   {
    objCache.Remove("GetTabs" + PortalId);
   }

   if (Cascade)
   {
    TabController objTabs = new TabController();
    TabInfo objTab;

    // 取得TabInfo集合
    ArrayList arrTabs = objTabs.GetTabs(PortalId);

    for (int intIndex = 0; intIndex < arrTabs.Count; intIndex++)
    {
     objTab = (TabInfo)arrTabs[intIndex];

     // 移除Tab缓存
     ClearTabCache(objTab.TabID);
    }
   }
  }

  /// <summary>
  /// 清除Tab缓存。
  /// </summary>
  /// <param name="TabId"></param>
  private static void ClearTabCache(int TabId)
  {
   Cache objCache = HttpRuntime.Cache;

   if (objCache["GetTab" + TabId] != null)
   {
    objCache.Remove("GetTab" + TabId);
   }

   if (objCache["GetPortalTabModules" + TabId] != null)
   {
    objCache.Remove("GetPortalTabModules" + TabId);
   }

   TabController objTabs = new TabController();

   // 取得TabInfo对象
   TabInfo objTab = objTabs.GetTab(TabId);

   if (objTab != null)
   {
    if (objCache["GetTabPermissionsByPortal" + objTab.PortalID] != null)
    {
     objCache.Remove("GetTabPermissionsByPortal" + objTab.PortalID);
    }
   }
  }

 }
}