public class CombineFiles : IHttpHandler {         private const string CacheKeyFormat = "_CacheKey_{0}_";         private const bool IsCompress = true; //需要压缩         public bool IsReusable         {             get             {                 return false;             }         }         public void ProcessRequest(HttpContext context)         {             HttpRequest request = context.Request;             HttpResponse response = context.Response;             string cachekey = string.Empty;             string type = request.QueryString["type"];             if (!string.IsNullOrEmpty(type) && (type == "css" || type == "js"))             {                 if (type == "js")                 {                     response.ContentType = "text/javascript";                 }                 else if (type == "css")                 {                     response.ContentType = "text/css";                 }                 cachekey = string.Format(CacheKeyFormat, type);                 CompressCacheItem cacheItem = HttpRuntime.Cache[cachekey] as CompressCacheItem;                 if (cacheItem == null)                 {                     string content = string.Empty;                     string path = context.Server.MapPath("");                     //找到这个目录下所有的js或css文件，当然也可以进行配置，需求请求压缩哪些文件                     //这里就将所的有文件都请求压缩                     string[] files = Directory.GetFiles(path, "*." + type);                     StringBuilder sb = new StringBuilder();                     foreach (string fileName in files)                     {                         if (File.Exists(fileName))                         {                             string readstr = File.ReadAllText(fileName, Encoding.UTF8);                             sb.Append(readstr);                         }                     }                     content = sb.ToString();                     // 开始压缩文件                     if (IsCompress)                     {                         if (type.Equals("js"))                         {                             content = JavaScriptCompressor.Compress(content);                         }                         else if (type.Equals("css"))                         {                             content = CssCompressor.Compress(content);                         }                     }                     //输入到客户端还可以进行Gzip压缩 ,这里就省略了                     cacheItem = new CompressCacheItem() { Type = type, Content = content, Expires = DateTime.Now.AddDays(30) };                     HttpRuntime.Cache.Insert(cachekey, cacheItem, null, cacheItem.Expires, TimeSpan.Zero);                 }                 string ifModifiedSince = request.Headers["If-Modified-Since"];                 if (!string.IsNullOrEmpty(ifModifiedSince)                     && TimeSpan.FromTicks(cacheItem.Expires.Ticks - DateTime.Parse(ifModifiedSince).Ticks).Seconds < 0)                 {                     response.StatusCode = (int)System.Net.HttpStatusCode.NotModified;                     response.StatusDescription = "Not Modified";                 }                 else                 {                     response.Write(cacheItem.Content);                     SetClientCaching(response, cacheItem.Expires);                 }             }         }         private void SetClientCaching(HttpResponse response, DateTime expires)         {             response.Cache.SetETag(DateTime.Now.Ticks.ToString());             response.Cache.SetLastModified(DateTime.Now);             //public 以指定响应能由客户端和共享（代理）缓存进行缓存。                response.Cache.SetCacheability(HttpCacheability.Public);             //是允许文档在被视为陈旧之前存在的最长绝对时间。             response.Cache.SetMaxAge(TimeSpan.FromTicks(expires.Ticks));             response.Cache.SetSlidingExpiration(true);         }         private class CompressCacheItem         {             /// <summary>             /// 类型 js 或 css             /// </summary>             public string Type { get; set; } // js css              /// <summary>             /// 内容             /// </summary>             public string Content { set; get; }             /// <summary>             /// 过期时间             /// </summary>             public DateTime Expires { set; get; }         } }

<script type="text/javascript" src="/js/CombineFiles.axd?type=js"></script> <link rel="stylesheet" type="text/css" href="/css/CombineFiles.axd?type=css" />