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

}

}