本文实例讲述了Asp.net程序优化js、css实现合并与压缩的方法。分享给大家供大家参考。具体实现方法如下：

访问时将js和css压缩并且缓存在客户端,

采用的是Yahoo.Yui.Compressor组件来完成的,用户可以点击此处本站下载。

创建一个IHttpHandler来处理文件

代码如下:

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; }

}

}

最后在配置文件中配置一下CombineFiles.axd文件，具体配置略

引用如下

复制代码 代码如下:<script type="text/javascript" src="/js/CombineFiles.axd?type=js"></script>

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

希望本文所述对大家的asp.net程序设计有所帮助。

更多信息请查看IT技术专栏