how to gzip content in asp.net MVC?

For .NET Core 2.1 there is a new package that can be used ( Microsoft.AspNetCore.ResponseCompression )

Simple sample to get going, after installing the package:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddResponseCompression();

        services.AddResponseCompression(options =>
        {
            options.Providers.Add<GzipCompressionProvider>();
            options.EnableForHttps = true;
        });
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseResponseCompression();
    }
}

You can read more about it here: https://docs.microsoft.com/en-us/aspnet/core/performance/response-compression?view=aspnetcore-2.1&tabs=aspnetcore2x

Have a look at this article which outlines a nifty method utilizing Action Filters.

For example:

[CompressFilter]
public void Category(string name, int? page)

And as an added bonus, it also includes a CacheFilter.

Here's what i use (as of this monent in time):

using  System.IO.Compression;

public class CompressAttribute : ActionFilterAttribute
{
    public override void OnActionExecuting(ActionExecutingContext filterContext)
    {

        var encodingsAccepted = filterContext.HttpContext.Request.Headers["Accept-Encoding"];
        if (string.IsNullOrEmpty(encodingsAccepted)) return;

        encodingsAccepted = encodingsAccepted.ToLowerInvariant();
        var response = filterContext.HttpContext.Response;

        if (encodingsAccepted.Contains("deflate"))
        {
            response.AppendHeader("Content-encoding", "deflate");
            response.Filter = new DeflateStream(response.Filter, CompressionMode.Compress);
        }
        else if (encodingsAccepted.Contains("gzip"))
        {
            response.AppendHeader("Content-encoding", "gzip");
            response.Filter = new GZipStream(response.Filter, CompressionMode.Compress);
        }
    }
}

usage in controller:

[Compress]
public class BookingController : BaseController
{...}

there are other varients, but this works quite well. (btw, i use the [Compress] attribute on my BaseController to save duplication across the project, whereas the above is doing it on a controller by controller basis.

[Edit] as mentioned in the para above. to simplify usage, you can also include [Compress] oneshot in the BaseController itself, thereby, every inherited child controller accesses the functionality by default:

[Compress]
public class BaseController : Controller
{...}