HttpRuntime.Cache的使用经验

配置文件

< appSettings >  

< add key = " EnableCache " value = " true " />  

< add key = " CacheDurationSeconds " value = " 300 " />

</ appSettings >

操作方法

 

代码

using System;

using System.Web.Configuration;
public class SiteHelper

{

    static public object GetCache( string CacheId)

    {

        object objCache = System.Web.HttpRuntime.Cache.Get(CacheId);
        // 判断 Cache 是否启用

        if (WebConfigurationManager.AppSettings[ " EnableCache " ] == null

            || ! Convert.ToBoolean(WebConfigurationManager.AppSettings[ " EnableCache " ]))

        {

            objCache = null ;

            System.Web.HttpRuntime.Cache.Remove(CacheId);

        }

        return objCache;

    }

    /// <summary>

    /// 写入 Cache 资料 ( 预设 60 秒 )

    /// </summary>

    /// <param name="CacheId"></param>

    /// <param name="objCache"></param>

    static public void SetCache( string CacheId, object objCache)

    {

        if (WebConfigurationManager.AppSettings[ " CacheDurationSeconds " ] != null )

        {

            SetCache(CacheId, objCache, Convert.ToInt32(WebConfigurationManager.AppSettings[ " CacheDurationSeconds " ]));

        }

        else

        {

            SetCache(CacheId, objCache, 60 );

        }

    }

    static public void SetCache( string CacheId, object objCache, int cacheDurationSeconds)

    {

        if (objCache != null )

        {

            System.Web.HttpRuntime.Cache.Insert(CacheId, objCache, null , System.Web.Caching.Cache.NoAbsoluteExpiration, new TimeSpan( 0 , 0 , cacheDurationSeconds), System.Web.Caching.CacheItemPriority.High, null );

        }

    }

}

使用方法

代码

string strCache1 = SiteHelper.GetCache( " Cache1 " ) as string ;
if (strCache1 == null ) {     Response.Write( " <p>Cache is empty</p> " );
    strCache1 = " OK " ;     SiteHelper.SetCache( " Cache1 " , strCache1, 30 ); }
Response.Write(strCache1);

常见问题#Cache显示与清空问题

代码

List < string > cacheKeys = new List < string > ();

IDictionaryEnumerator cacheEnum = Cache.GetEnumerator();

while (cacheEnum.MoveNext())

{

    cacheKeys.Add(cacheEnum.Key.ToString());

}

foreach ( string cacheKey in cacheKeys)

{

    Cache.Remove(cacheKey);

}

代码

    // 清除所有缓存

    protected void RemoveAllCache()

    {

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

        IDictionaryEnumerator CacheEnum = _cache.GetEnumerator();

        ArrayList al = new ArrayList();

        while (CacheEnum.MoveNext())

        {

            al.Add(CacheEnum.Key);

        }

        foreach ( string key in al)

        {

            _cache.Remove(key);

        }

        show();

    }    

// 显示所有缓存

    void show()

    {

        string str = "" ;

        IDictionaryEnumerator CacheEnum = HttpRuntime.Cache.GetEnumerator();

        while (CacheEnum.MoveNext())

        {

            str += " 缓存名<b>[ " + CacheEnum.Key + " ]</b><br /> " ;

        }

        this .Label1.Text = " 当前网站总缓存数: " + HttpRuntime.Cache.Count + " <br /> " + str;

    }

添加到扩展方法

代码

using System;

using System.Web.Caching;

using System.Collections;

using System.Collections.Generic;

/// <summary>

/// 扩充 System.Web.Caching 命名空间的 Extension Methods

/// </summary>

static public class CacheExtensionMethod

{

    public static void Clear( this Cache x)

    {

        List < string > cacheKeys = new List < string > ();

        IDictionaryEnumerator cacheEnum = x.GetEnumerator();

        while (cacheEnum.MoveNext())

        {

            cacheKeys.Add(cacheEnum.Key.ToString());

        }

        foreach ( string cacheKey in cacheKeys)

        {

            x.Remove(cacheKey);

        }

    }

}

 

转自：http://blog.csdn.net/fengloveyun/article/details/5934158