访问时将js和css压缩并且缓存在客户端,
采用的是Yahoo.Yui.Compressor组件还完成的,从可下载创建一个IHttpHandler来处理文件
1 public class CombineFiles : IHttpHandler 2 { 3 private const string CacheKeyFormat = " _CacheKey_{0}_ "; 4 5 private const bool IsCompress = true; // 需要压缩 6 7 public bool IsReusable 8 { 9 get 10 { 11 return false; 12 } 13 } 14 15 public void ProcessRequest(HttpContext context) 16 { 17 HttpRequest request = context.Request; 18 HttpResponse response = context.Response; 19 20 string cachekey = string.Empty; 21 22 string type = request.QueryString[ " type "]; 23 if (! string.IsNullOrEmpty(type) && (type == " css " || type == " js ")) 24 { 25 if (type == " js ") 26 { 27 response.ContentType = " text/javascript "; 28 29 } 30 else if (type == " css ") 31 { 32 response.ContentType = " text/css "; 33 } 34 35 cachekey = string.Format(CacheKeyFormat, type); 36 37 CompressCacheItem cacheItem = HttpRuntime.Cache[ cachekey] as CompressCacheItem; 38 if (cacheItem == null) 39 { 40 string content = string.Empty; 41 string path = context.Server.MapPath( ""); 42 // 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 43 // 这里就将所的有文件都请求压缩 44 string[] files = Directory.GetFiles(path, " *. " + type); 45 StringBuilder sb = new StringBuilder(); 46 foreach ( string fileName in files) 47 { 48 if (File.Exists(fileName)) 49 { 50 string readstr = File.ReadAllText(fileName, Encoding.UTF8); 51 sb.Append(readstr); 52 } 53 } 54 55 content = sb.ToString(); 56 57 // 开始压缩文件 58 if (IsCompress) 59 { 60 if (type.Equals( " js ")) 61 { 62 content = JavaScriptCompressor.Compress(content); 63 } 64 else if (type.Equals( " css ")) 65 { 66 content = CssCompressor.Compress(content); 67 } 68 } 69 70 // 输入到客户端还可以进行Gzip压缩 ,这里就省略了 71 72 cacheItem = new CompressCacheItem() { Type = type, Content = content, Expires = DateTime.Now.AddDays( 30) }; 73 HttpRuntime.Cache.Insert(cachekey, cacheItem, null, cacheItem.Expires, TimeSpan.Zero); 74 } 75 76 string ifModifiedSince = request.Headers[ " If-Modified-Since "]; 77 if (! string.IsNullOrEmpty(ifModifiedSince) 78 && TimeSpan.FromTicks(cacheItem.Expires.Ticks - DateTime.Parse(ifModifiedSince).Ticks).Seconds < 0) 79 { 80 response.StatusCode = ( int)System.Net.HttpStatusCode.NotModified; 81 response.StatusDescription = " Not Modified "; 82 } 83 else 84 { 85 response.Write(cacheItem.Content); 86 SetClientCaching(response, cacheItem.Expires); 87 } 88 } 89 90 } 91 92 private void SetClientCaching(HttpResponse response, DateTime expires) 93 { 94 response.Cache.SetETag(DateTime.Now.Ticks.ToString()); 95 response.Cache.SetLastModified(DateTime.Now); 96 97 // public 以指定响应能由客户端和共享（代理）缓存进行缓存。 98 response.Cache.SetCacheability(HttpCacheability.Public); 99 100 // 是允许文档在被视为陈旧之前存在的最长绝对时间。 101 response.Cache.SetMaxAge(TimeSpan.FromTicks(expires.Ticks)); 102 103 response.Cache.SetSlidingExpiration( true); 104 } 105 private class CompressCacheItem 106 { 107 /// <summary> 108 /// 类型 js 或 css 109 /// </summary> 110 public string Type { get; set; } // js css 111 /// <summary> 112 /// 内容 113 /// </summary> 114 public string Content { set; get; } 115 /// <summary> 116 /// 过期时间 117 /// </summary> 118 public DateTime Expires { set; get; } 119 } 120 }