using System;
using System.IO.Compression;
using System.Web.Mvc;

namespace MvcApplication1
{
    public class GZipAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext context)
        {
            var acceptEncoding = context.HttpContext.Request.Headers["Accept-Encoding"];
            if (!string.IsNullOrEmpty(acceptEncoding))
            {
                acceptEncoding = acceptEncoding.ToLower();
                var response = context.HttpContext.Response;
                if (acceptEncoding.Contains("gzip"))
                {
                    response.AppendHeader("Content-Encoding", "gzip");
                    response.Filter = new GZipStream(response.Filter, CompressionMode.Compress);
                }
                else if (acceptEncoding.Contains("deflate"))
                {
                    response.AppendHeader("Content-Encoding", "deflate");
                    response.Filter = new DeflateStream(response.Filter, CompressionMode.Compress);
                }
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace MvcApplication1.Controllers
{
    public class HomeController : Controller
    {
        [GZip]
        public ActionResult Index()
        {
            ViewBag.Message = "欢迎使用 ASP.NET MVC!";

            return View();
        }

        public ActionResult About()
        {
            return View();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;

namespace MvcApplication1
{
    public class MvcApplication : System.Web.HttpApplication
    {
        public static void RegisterGlobalFilters(GlobalFilterCollection filters)
        {
            filters.Add(new HandleErrorAttribute());
            filters.Add(new GZipAttribute());
        }

        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                "Default", // 路由名称
                "{controller}/{action}/{id}", // 带有参数的 URL
                new { controller = "Home", action = "Index", id = UrlParameter.Optional } // 参数默认值
            );

        }

        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();

            RegisterGlobalFilters(GlobalFilters.Filters);
            RegisterRoutes(RouteTable.Routes);
        }
    }
}