Cách mà tôi thường dùng nhất để nén Gzip cho website và rất hiệu quả đó là nén Gzip trong Global.asax. Đầu tiên trong thư mục App_Code các bạn tạo thêm một class có tên GlobalGZip.cs với nội dung như sau:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.IO;
using System.IO.Compression;
/// <summary>
/// Summary description for GlobalGZip
/// </summary>
public class GlobalGZip : System.Web.HttpApplication
{
public GlobalGZip()
{
InitializeComponent();
}
private void InitializeComponent()
{
this.PostReleaseRequestState += new EventHandler(Global_PostReleaseRequestState);
}
/// <summary>
/// Event handler for PostReleaseRequestState
/// </summary>
private void Global_PostReleaseRequestState(object sender, EventArgs e)
{
string contentType = Response.ContentType; // Get the content type.
// Compress only html and stylesheet documents.
if (contentType == "text/html" || contentType == "text/css")
{
// Get the Accept-Encoding header value to know whether zipping is supported by the browser or not.
string acceptEncoding = Request.Headers["Accept-Encoding"];
if (!string.IsNullOrEmpty(acceptEncoding))
{
// If gzip is supported then gzip it else if deflate compression is supported then compress in that technique.
if (acceptEncoding.Contains("gzip"))
{
// Compress and set Content-Encoding header for the browser to indicate that the document is zipped.
Response.Filter = new GZipStream(Response.Filter, CompressionMode.Compress);
Response.AppendHeader("Content-Encoding", "gzip");
}
else if (acceptEncoding.Contains("deflate"))
{
// Compress and set Content-Encoding header for the browser to indicate that the document is zipped.
Response.Filter = new DeflateStream(Response.Filter, CompressionMode.Compress);
Response.AppendHeader("Content-Encoding", "deflate");
}
}
}
}
}
