asp之缓存 cachestate

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string CacheKey = "cachetest";
        object objModel = GetCache(CacheKey);//从缓存中获取
        if (objModel == null)//缓存里没有
        {
            objModel = DateTime.Now;//把当前时间进行缓存
            if (objModel != null)
            {
                int CacheTime = 30;//缓存时间30秒
                SetCache(CacheKey, objModel, DateTime.Now.AddSeconds(CacheTime), TimeSpan.Zero);//写入缓存
            }
        }
        Label1.Text = objModel.ToString();

    }
    /// <summary>
    /// 获取当前应用程序指定CacheKey的Cache对象值 
    /// </summary>
    /// <param name="CacheKey">索引键值</param>
    /// <returns>返回缓存对象</returns> 
    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对象值
    /// </summary>
    /// <param name="CacheKey">索引键值</param>
    /// <param name="objObject">缓存对象</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对象值
    /// </summary>
    /// <param name="CacheKey">索引键值</param>
    /// <param name="objObject">缓存对象</param>
    /// <param name="absoluteExpiration">绝对过期时间</param>
    /// <param name="slidingExpiration">最后一次访问所插入对象时与该对象过期时之间的时间间隔</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);
    }
}