本文實(shí)例講述了Asp.net程序優(yōu)化js、css實(shí)現(xiàn)合并與壓縮的方法。分享給大家供大家參考。具體實(shí)現(xiàn)方法如下：

訪問時將js和css壓縮并且緩存在客戶端,

采用的是Yahoo.Yui.Compressor組件來完成的,用戶可以點(diǎn)擊此處本站下載。

創(chuàng)建一個IHttpHandler來處理文件

代碼如下:

public class CombineFiles : IHttpHandler

{

private const string CacheKeyFormat = "_CacheKey_{0}_";

private const bool IsCompress = true; //需要壓縮

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("");

//找到這個目錄下所有的js或css文件，當(dāng)然也可以進(jìn)行配置，需求請求壓縮哪些文件

//這里就將所的有文件都請求壓縮

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();

// 開始壓縮文件

if (IsCompress)

{

if (type.Equals("js"))

{

content = JavaScriptCompressor.Compress(content);

}

else if (type.Equals("css"))

{

content = CssCompressor.Compress(content);

}

}

//輸入到客戶端還可以進(jìn)行Gzip壓縮 ,這里就省略了

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 以指定響應(yīng)能由客戶端和共享（代理）緩存進(jìn)行緩存。

response.Cache.SetCacheability(HttpCacheability.Public);

//是允許文檔在被視為陳舊之前存在的最長絕對時間。

response.Cache.SetMaxAge(TimeSpan.FromTicks(expires.Ticks));

response.Cache.SetSlidingExpiration(true);

}

private class CompressCacheItem

{

/// <summary>

/// 類型 js 或 css

/// </summary>

public string Type { get; set; } // js css

/// <summary>

/// 內(nèi)容

/// </summary>

public string Content { set; get; }

/// <summary>

/// 過期時間

/// </summary>

public DateTime Expires { set; get; }

}

}

最后在配置文件中配置一下CombineFiles.axd文件，具體配置略

引用如下

復(fù)制代碼 代碼如下:<script type="text/javascript" src="/js/CombineFiles.axd?type=js"></script>

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

希望本文所述對大家的asp.net程序設(shè)計(jì)有所幫助。

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