C# 缓存

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Caching;
using System.Web.Hosting;
/// <summary>
/// Caching 的摘要说明
/// </summary>
public class Caching
{

    /// <summary>
    /// 获取当前应用程序指定CacheKey的Cache值
    /// </summary>
    /// <param name="CacheKey"></param>
    /// <returns></returns>y
    public static object GetCache(string CacheKey)
    {
        System.Web.Caching.Cache objCache = HttpRuntime.Cache;
        return objCache[CacheKey];
    }

    /// <summary>
    /// 设置当前应用程序指定CacheKey的Cache值
    /// </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>
    /// 设置当前应用程序指定CacheKey的Cache值
    /// </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>
    /// 清除单一键缓存
    /// </summary>
    /// <param name="key"></param>
    public static void RemoveKeyCache(string CacheKey)
    {
        try
        {
            System.Web.Caching.Cache objCache = HttpRuntime.Cache;
            objCache.Remove(CacheKey);
        }
        catch { }
    }

    /// <summary>
    /// 清除所有缓存
    /// </summary>
    public static void RemoveAllCache()
    {
        System.Web.Caching.Cache _cache = HttpRuntime.Cache;
        IDictionaryEnumerator CacheEnum = _cache.GetEnumerator();
        if (_cache.Count > 0)
        {
            ArrayList al = new ArrayList();
            while (CacheEnum.MoveNext())
            {
                al.Add(CacheEnum.Key);
            }
            foreach (string key in al)
            {
                _cache.Remove(key);
            }
        }
    }

    /// <summary>
    /// 以列表形式返回已存在的所有缓存 
    /// </summary>
    /// <returns></returns> 
    public static ArrayList ShowAllCache()
    {
        ArrayList al = new ArrayList();
        System.Web.Caching.Cache _cache = HttpRuntime.Cache;
        if (_cache.Count > 0)
        {
            IDictionaryEnumerator CacheEnum = _cache.GetEnumerator();
            while (CacheEnum.MoveNext())
            {
                al.Add(CacheEnum.Key);
            }
        }
        return al;
    }


}

absoluteExpiration
类型：System.DateTime
所添加对象将过期并被从缓存中移除的时间。如果使用可调过期，则 absoluteExpiration 参数必须为 NoAbsoluteExpiration。

slidingExpiration
类型：System.TimeSpan
最后一次访问所添加对象时与该对象过期时之间的时间间隔。如果该值等效于 20 分钟，则对象在最后一次被访问 20 分钟之后将过期并从缓存中移除。如果使用绝对过期，则 slidingExpiration 参数必须为 NoSlidingExpiration。