webapi basecontroller c#

gistfile1.txt

using System;
using System.Web;
using System.Web.Http;
using System.Web.Http.Controllers;
using System.Web.Http.Routing;
using System.Web.Http.WebHost;
using System.Web.Routing;
using System.Web.SessionState;

namespace filetransfer
{
    public static class webApiConfig
    {
        public class BaseController : ApiController
        {

        }
            
        public static string prefix = "webapi";
        public class WebApiCustomDirectRouteProvider : System.Web.Http.Routing.DefaultDirectRouteProvider
        {
            protected override System.Collections.Generic.IReadOnlyList<System.Web.Http.Routing.IDirectRouteFactory>
                GetActionRouteFactories(System.Web.Http.Controllers.HttpActionDescriptor actionDescriptor)
            {
                return actionDescriptor.GetCustomAttributes<System.Web.Http.Routing.IDirectRouteFactory>(inherit: true);
            }
            private readonly string _centralizedPrefix;

            public WebApiCustomDirectRouteProvider(string centralizedPrefix)
            {
                _centralizedPrefix = centralizedPrefix;
            }

            protected override string GetRoutePrefix(HttpControllerDescriptor controllerDescriptor)
            {
                var existingPrefix = base.GetRoutePrefix(controllerDescriptor);
                if (existingPrefix == null) return _centralizedPrefix;

                return string.Format("{0}/{1}", _centralizedPrefix, existingPrefix);
            }
        }


        public static void Register(HttpConfiguration config)
        {
            //Vererbung erlauben
            config.MapHttpAttributeRoutes(new WebApiCustomDirectRouteProvider("webapi"));

            //Zugriff auf Session ermöglichen
            var httpControllerRouteHandler = typeof(HttpControllerRouteHandler).GetField("_instance", System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic); if (httpControllerRouteHandler != null)
            { httpControllerRouteHandler.SetValue(null, new Lazy<HttpControllerRouteHandler>(() => new SessionHttpControllerRouteHandler(), true)); }

            //json statt xml ausgeben
            config.Formatters.JsonFormatter.MediaTypeMappings
.Add(new System.Net.Http.Formatting.RequestHeaderMapping("Accept", "text/html", StringComparison.InvariantCultureIgnoreCase, true, "application/json"));
        }

        #region Sitzung im webApi

        public class SessionControllerHandler : HttpControllerHandler, IRequiresSessionState
        {
            public SessionControllerHandler(RouteData routeData) : base(routeData)
            { }
        }

        public class SessionHttpControllerRouteHandler : HttpControllerRouteHandler
        {
            protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
            { return new SessionControllerHandler(requestContext.RouteData); }
        }

        #endregion Sitzung im webApi
    }
}