代码：
SiteCache.cs
using System;using System.Collections;using System.Text.RegularExpressions;using System.Web;using System.Web.Caching;namespace Ycweb.Components
{
public class SiteCache
{ private static readonly Cache _cache; public static readonly int DayFactor; private static int Factor; public static readonly int HourFactor; public static readonly int MinuteFactor; static SiteCache() { DayFactor = 17280; HourFactor = 720; MinuteFactor = 12; Factor = 5; _cache = HttpRuntime.Cache;
} private SiteCache() { } public static void Clear() { IDictionaryEnumerator enumerator = _cache.GetEnumerator(); while (enumerator.MoveNext()) { _cache.Remove(enumerator.Key.ToString()); } } public static object Get(string key) { return _cache[key]; } public static void Insert(string key, object obj) { Insert(key, obj, null, 1); } public static void Insert(string key, object obj, int seconds) { Insert(key, obj, null, seconds); } public static void Insert(string key, object obj, CacheDependency dep) { Insert(key, obj, dep, HourFactor*12); } public static void Insert(string key, object obj, int seconds, CacheItemPriority priority) { Insert(key, obj, null, seconds, priority); } public static void Insert(string key, object obj, CacheDependency dep, int seconds) { Insert(key, obj, dep, seconds, CacheItemPriority.Normal); } public static void Insert(string key, object obj, CacheDependency dep, int seconds, CacheItemPriority priority) { if (obj != null) { _cache.Insert(key, obj, dep, DateTime.Now.AddSeconds((double) (Factor*seconds)), TimeSpan.Zero, priority, null); } } public static void Max(string key, object obj) { Max(key, obj, null); } public static void Max(string key, object obj, CacheDependency dep) { if (obj != null) { _cache.Insert(key, obj, dep, DateTime.MaxValue, TimeSpan.Zero, CacheItemPriority.AboveNormal, null); } } public static void MicroInsert(string key, object obj, int secondFactor) { if (obj != null) { _cache.Insert(key, obj, null, DateTime.Now.AddSeconds((double) (Factor*secondFactor)), TimeSpan.Zero); } } public static void Remove(string key) { _cache.Remove(key); } public static void RemoveByPattern(string pattern) { IDictionaryEnumerator enumerator = _cache.GetEnumerator(); Regex regex1 = new Regex(pattern, RegexOptions.Singleline | RegexOptions.Compiled | RegexOptions.IgnoreCase); while (enumerator.MoveNext()) { if (regex1.IsMatch(enumerator.Key.ToString())) { _cache.Remove(enumerator.Key.ToString()); } } } public static void ReSetFactor(int cacheFactor) { Factor = cacheFactor; } }
}
有了SiteCache类，接下来看看如何使用它。还是以读取新闻TonN列表为例：
public static RecordSet GetNewsSetTopN(string classCode,int topN,SortPostsBy orderBy, SortOrder sortOrder, string language){ string cacheKey = string.Format("NewsSetTopN-LG:{0}:CC:{1}:TN:{2}:OB:{3}:SO:{4}", language,classCode,topN.ToString(), orderBy.ToString(),sortOrder.ToString()); //从上下文中读缓存项 RecordSet newsSet = HttpContext.Current.Items[cacheKey] as RecordSet; if (newsSet == null) { //从HttpRuntime.Cache读缓存项 newsSet = SiteCache.Get(cacheKey) as RecordSet; if (newsSet == null) { //直接从数据库从读取 CommonDataProvider dp=CommonDataProvider.Instance(); newsSet =dp.GetNewsSetTopN(language,classCode,topN,orderBy,sortOrder); //并将结果缓存到HttpRuntime.Cache中 SiteCache.Insert(cacheKey, newsSet, 60, CacheItemPriority.Normal); } }return newsSet;}
/**//// <summary>/// 删除匹配的NewsSetTopN列表的Cache项/// </summary>public static void ClearNewsSetTopNCache(string language,string classCode,int topN){ string cacheKey = string.Format("NewsSetTopN-LG:{0}:CC:{1}:TN:{2}",language,classCode,topN.ToString()); SiteCache.RemoveByPattern(cacheKey);}
发布新闻后调用静态方法ClearNewsSetTopNCache()强行清除原来的TopN缓存项，例如：
/**//// <summary>/// 发布(新建)新闻/// </summary>/// <param name="post">新闻实例</param>/// <returns>返回状态</returns>public static int Create(News post){ int status; CommonDataProvider dp=CommonDataProvider.Instance(); dp.CreateUpdateDeleteNews(post, DataAction.Create, out status); //强制清除匹配的缓存项 ClearNewsSetTopNCache (post.Language, post.ClassCode,Globals.GetSiteSetting.NewsListTopN); return status;}
That"s all.若有不妥之处还望各位同行指正。
