asp.net 缓存公共类

using System;

using System.Collections.Generic;

using System.Text;

using System.Web;

using System.Web.Caching;

using System.IO;

namespace Tools.Web

{

    /// <summary> 

    /// 网页中的缓存类,使用示例： 

    /// object obj = DataCache.GetCache("file1",depfile); 

    ///if (obj == null) 

    ///{ 

    ///   string txt = "缓存内容";//从数据库或文件读取到的内容 

    ///   DataCache.SetCacheDepFile("file1", txt, depfile); 

    /// } 

    /// else 

    /// { 

    ///     string txt=obj.ToString(); 

    /// } 

    /// </summary> 

    ///

    public partial class DataCache

    {

        #region 文件路径web.config

        private static string _webconfigfile = string.Empty;

        /// <summary> 

        /// 文件路径web.config 

        /// </summary> 

        public static string webconfigfile

        {

            get

            {

                if (string.IsNullOrEmpty(_webconfigfile)) _webconfigfile = HttpContext.Current.Server.MapPath("/web.config");

                return _webconfigfile;

            }

        }

        #endregion

#region 文件路径App_Data/ShopConfig.config

        private static string _shopconfigfile = string.Empty;

        /// <summary> 

        /// 文件路径App_Data/ShopConfig.config 

        /// </summary> 

        public static string shopconfigfile

        {

            get

            {

                if (string.IsNullOrEmpty(_shopconfigfile)) _shopconfigfile = HttpContext.Current.Server.MapPath("/App_Data/ShopConfig.config");

                return _shopconfigfile;

            }

        }

        #endregion

#region 文件路径App_Data/SiteConfig.config

        private static string _siteconfigfile = string.Empty;

        /// <summary> 

        /// 文件路径App_Data/SiteConfig.config 

        /// </summary> 

        public static string siteconfigfile

        {

            get

            {

                if (string.IsNullOrEmpty(_siteconfigfile)) _siteconfigfile = HttpContext.Current.Server.MapPath("/App_Data/SiteConfig.config");

                return _siteconfigfile;

            }

        }

        #endregion

#region 文件路径App_Data/Template.config

        private static string _templateconfigfile = string.Empty;

        /// <summary> 

        /// 文件路径App_Data/Template.config 

        /// </summary> 

        public static string templateconfigfile

        {

            get

            {

                if (string.IsNullOrEmpty(_templateconfigfile)) _templateconfigfile = HttpContext.Current.Server.MapPath("/App_Data/Template.config");

                return _templateconfigfile;

            }

        }

        #endregion

#region 删除缓存

        /// <summary> 

        /// 删除缓存 

        /// </summary> 

        /// <param name="CacheKey">键</param> 

        public static void DeleteCache(string CacheKey)

        {

            HttpRuntime.Cache.Remove(CacheKey);

        }

        #endregion

#region 获取缓存，依赖时间

        /// <summary> 

        /// 获取缓存，依赖时间 

        /// </summary> 

        /// <param name="CacheKey">键</param> 

        /// <returns></returns> 

        public static object GetCache(string CacheKey)

        {

            object obj_time = HttpRuntime.Cache[CacheKey + "_time"];

            object obj_cache = HttpRuntime.Cache[CacheKey];

            if (obj_time != null && obj_cache != null)

            {

                if (Convert.ToDateTime(obj_time) < DateTime.Now)

                {

                    DeleteCache(CacheKey);

                    DeleteCache(CacheKey + "_time");

                    return null;

                }

                else return obj_cache;

            }

            else

            {

                DeleteCache(CacheKey);

                DeleteCache(CacheKey + "_time");

                return null;

            }

        }

        #endregion

#region 获取缓存，依赖文件

        /// <summary> 

        /// 获取缓存，依赖文件 

        /// </summary> 

        /// <param name="CacheKey">键</param> 

        /// <param name="depFile">依赖的文件</param> 

        /// <returns></returns> 

        public static object GetCache(string CacheKey, string depFile)

        {

            object obj_time = HttpRuntime.Cache[CacheKey + "_time"];

            object obj_cache = HttpRuntime.Cache[CacheKey];

            if (File.Exists(depFile))

            {

                FileInfo fi = new FileInfo(depFile);

if (obj_time != null && obj_cache != null)

                {

                    if (Convert.ToDateTime(obj_time) != fi.LastWriteTime)

                    {

                        DeleteCache(CacheKey);

                        DeleteCache(CacheKey + "_time");

                        return null;

                    }

                    else return obj_cache;

                }

                else

                {

                    DeleteCache(CacheKey);

                    DeleteCache(CacheKey + "_time");

                    return null;

                }

            }

            else

            {

                throw new Exception("文件(" + depFile + ")不存在！");

            }

        }

        #endregion

#region 简单的插入缓存

        /// <summary> 

        /// 简单的插入缓存 

        /// </summary> 

        /// <param name="CacheKey">键</param> 

        /// <param name="objObject">数据</param> 

        public static void SetCache(string CacheKey, object objObject)

        {

            HttpRuntime.Cache.Insert(CacheKey, objObject);

        }

        #endregion

#region 有过期时间的插入缓存数据

        /// <summary> 

        /// 有过期时间的插入缓存数据 

        /// </summary> 

        /// <param name="CacheKey">键</param> 

        /// <param name="objObject">数据</param> 

        /// <param name="absoluteExpiration">过期时间</param> 

        /// <param name="slidingExpiration">可调度参数，传null就是禁用可调度</param> 

        public static void SetCache(string CacheKey, object objObject, DateTime absoluteExpiration, TimeSpan slidingExpiration)

        {

            if (slidingExpiration == null) slidingExpiration = Cache.NoSlidingExpiration;

            HttpRuntime.Cache.Insert(CacheKey, objObject, null, absoluteExpiration, slidingExpiration);

            HttpRuntime.Cache.Insert(CacheKey + "_time", absoluteExpiration, null, absoluteExpiration, slidingExpiration);//存储过期时间 

        }

        #endregion

#region 插入缓存数据，指定缓存多少秒

        /// <summary> 

        /// 插入缓存数据，指定缓存多少秒 

        /// </summary> 

        /// <param name="CacheKey">缓存的键</param> 

        /// <param name="objObject">缓存的数据</param> 

        /// <param name="seconds">缓存秒数</param> 

        /// <param name="slidingExpiration">传null就是禁用可调度过期</param> 

        public static void SetCacheSecond(string CacheKey, object objObject, int seconds, TimeSpan slidingExpiration)

        {

            DateTime absoluteExpiration = DateTime.Now.AddSeconds(seconds);

            if (slidingExpiration == null) slidingExpiration = Cache.NoSlidingExpiration;

            HttpRuntime.Cache.Insert(CacheKey, objObject, null, absoluteExpiration, slidingExpiration);

            HttpRuntime.Cache.Insert(CacheKey + "_time", absoluteExpiration, null, absoluteExpiration, slidingExpiration);//存储过期时间 

        }

        #endregion

#region 依赖文件的缓存，文件没改不会过期

        /// <summary> 

        /// 依赖文件的缓存，文件没改不会过期 

        /// </summary> 

        /// <param name="CacheKey">键</param> 

        /// <param name="objObject">数据</param> 

        /// <param name="depfilename">依赖文件，可调用 DataCache 里的变量</param> 

        public static void SetCacheDepFile(string CacheKey, object objObject, string depfilename)

        {

            //缓存依赖对象 

            System.Web.Caching.CacheDependency dep = new System.Web.Caching.CacheDependency(depfilename);

            DateTime absoluteExpiration = System.Web.Caching.Cache.NoAbsoluteExpiration;

            TimeSpan slidingExpiration = System.Web.Caching.Cache.NoSlidingExpiration;

            System.Web.Caching.Cache objCache = HttpRuntime.Cache;

            objCache.Insert(

                CacheKey,

                objObject,

                dep,

                System.Web.Caching.Cache.NoAbsoluteExpiration, //从不过期 

                slidingExpiration, //禁用可调过期 

                System.Web.Caching.CacheItemPriority.Default,

                null);

            if (File.Exists(depfilename))

            {

                FileInfo fi = new FileInfo(depfilename);

                DateTime lastWriteTime = fi.LastWriteTime;

                HttpRuntime.Cache.Insert(CacheKey + "_time", lastWriteTime, null, absoluteExpiration, slidingExpiration);//存储文件最后修改时间 

            }

}

        #endregion

    }

}