Minify Action Filter Attribute in ASP.NET MVC

[HandleError]
public class HomeController : Controller
{
[Minify]
public ActionResult Index()
{
ViewData["Message"] = "Welcome to ASP.NET MVC!";

return View();
}
}

public class Minify : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
if (response.ContentType == "text/html")

filterContext.HttpContext.Response.Filter = new MinifyFilter(filterContext.HttpContext.Response.Filter);

base.OnActionExecuting(filterContext);
}
}

public class MinifyFilter : MemoryStream
{
private StringBuilder outputString = new StringBuilder();
private Stream outputStream = null;

public MinifyFilter(Stream outputStream)
{
this.outputStream = outputStream;
}

public override void Write(byte[] buffer, int offset, int count)
{
outputString.Append(Encoding.UTF8.GetString(buffer));
}

public override void Close()
{
//Call the minifier here, your data is in outputString
string result = outputString.ToString().Replace(Environment.NewLine, string.Empty);

byte[] rawResult = Encoding.UTF8.GetBytes(result);
outputStream.Write(rawResult, 0, rawResult.Length);

base.Close();
outputStream.Close();
}
}

#region Dirty work
public override void Write(byte[] buffer, int offset, int count)
{
HttpResponse response = HttpContext.Current.Response;
string charset = response.Charset ?? "utf-8";
string finalHtml = Encoding.GetEncoding(charset).GetString(buffer, offset, count);
Regex eof = new Regex("</html>", RegexOptions.IgnoreCase);

if (!eof.IsMatch(finalHtml))
{
responseHtml.Append(finalHtml);
}
else
{
responseHtml.Append(finalHtml);
finalHtml = responseHtml.ToString();
//js文本
Regex reg = new Regex("<script[^>]*>(?<content>[^<]*)</script>", RegexOptions.IgnoreCase | RegexOptions.Multiline);
//js引用
Regex regSrc = new Regex("src=\"?(?<src>[^'\">]*)\"?", RegexOptions.IgnoreCase | RegexOptions.Multiline);
StringBuilder jsContent = new StringBuilder();
List<string> jsSrc = new List<string>();

MatchCollection mc = reg.Matches(finalHtml);

if (mc.Count > 0)
{
#region 找出js部分

foreach (Match m in mc)
{
string str = m.Groups["content"].Value;
if (!string.IsNullOrEmpty(str))
{
jsContent.AppendLine(str);//找出js文本
}
else
{
//找出js引用
Match mSrc = regSrc.Match(m.Value);
if (mSrc != null && mSrc.Success)
{
string temp = mSrc.Groups["src"].Value;
if (!jsSrc.Contains(temp))
jsSrc.Add(temp);
}
}
}
#endregion

finalHtml = reg.Replace(finalHtml, string.Empty);

#region 合并js文本和js引用

//生成新的js引用
string jsFileFormat = "<script type=\"text/javascript\" src=\"{0}\"></script>";
string jshref = string.Format(jsFileFormat, "http://localhost:58798/js.ashx?href=" + string.Join(",", jsSrc));
//生成新的js文本
string jstextFormat = "<script type=\"text/javascript\">{0}</script>";
//压缩js文本
string jsContentstr = JavaScriptCompressor.Compress(jsContent.ToString());
string jsText = string.Format(jstextFormat, jsContentstr);
//插入新生成的js
int bodyindex = finalHtml.ToLower().LastIndexOf("</body>");
finalHtml = finalHtml.Insert(bodyindex, jshref + Environment.NewLine + jsText);
#endregion
}
byte[] data = Encoding.GetEncoding(charset).GetBytes(finalHtml);
responseStream.Write(data, 0, data.Length);
}

}

#endregion

string str = Request.Headers.Get("Accept-Encoding");
if (str != null)
{
Stream filter = Response.Filter;
str = str.ToLower();
if (str.Contains("gzip"))
{
Response.Filter = new GZipStream(filter, CompressionMode.Compress);
Response.AppendHeader("Content-Encoding", "gzip");
}
else if (str.Contains("deflate"))
{
Response.Filter = new DeflateStream(filter, CompressionMode.Compress);
Response.AppendHeader("Content-Encoding", "deflate");
}
}