Problem with Custom Routes and Httphandler in ASP.NET MVC

Question

On a project I’m working on, I wrote a HttpHandler to bring as a response an image instead of a View, sort of like this:

using System;
using System.Web;
using System.Web.Routing;
using MeuProjeto.Data;
using MeuProjeto.Infrastructure;

namespace MeuProjeto.HttpHandlers
{
    public class ImagemFuncionarioHttpHandler : IHttpHandler
    {
        public RequestContext RequestContext { get; set; }

        public ImagemFuncionarioHttpHandler(RequestContext requestContext)
        {
            RequestContext = requestContext;
        }

        /// <summary>
        /// 
        /// </summary>
        public bool IsReusable
        {
            get { return false; }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="context"></param>
        public void ProcessRequest(HttpContext context)
        {
            var currentResponse = HttpContext.Current.Response;

            currentResponse.ContentType = "image/jpeg";
            currentResponse.Buffer = true;

            var usuarioId = Convert.ToInt32(RequestContext.RouteData.GetRequiredString("id"));

            try
            {
                var funcionario = new Funcionarios(GeneralSettings.DataBaseConnection).SelecionarPorId(usuarioId);

                currentResponse.BinaryWrite(funcionario.ThumbnailFuncionario);
                currentResponse.Flush();
            }
            catch (Exception ex)
            {
                context.Response.Write(ex.StackTrace);
            }
        }
    }
}

To run a route, this HttpHandler needs a RouteHandler:

using System.Web;
using System.Web.Routing;
using MeuProjeto.HttpHandlers;

namespace MeuProjeto.RouteHandlers
{
    public class ImagemFuncionarioRouteHandler : IRouteHandler 
    {
        public IHttpHandler GetHttpHandler(RequestContext requestContext)
        {
            return new ImagemFuncionarioHttpHandler(requestContext);
        }
    }
}

And the route configuration looks like this:

using System.Web.Mvc;
using System.Web.Routing;
using MeuProjeto.Helpers;
using MeuProjeto.RouteHandlers;

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

            routes.Add(new Route("Funcionarios/Thumbnail/{id}", new ImagemFuncionarioRouteHandler()));

            routes.MapRouteWithName(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

The above code works perfectly if I enter the following address:

http://meudominio.com.br/Funcionarios/Thumbnail/1

Only every time I use the route on whatever screen it is, the actions of forms spoil by redirecting the POST request to this address http://meudominio.com.br/Funcionarios/Thumbnail/1?action=Index&controller=Vagas.

What should I do?

Answer 1

I asked the same question in the gringo OS and was told by comment that the approach should be changed. No need HttpHandlers, modify routes or anything like that. Simply doing the Controller return a FileResult already solves the problem:

public FileResult Thumbnail(int id)
{
    var funcionario = new Funcionarios(GeneralSettings.DataBaseConnection).SelecionarPorId(id);
    return File(funcionario.ThumbnailFuncionario, System.Net.Mime.MediaTypeNames.Image.Jpeg);
}