title: HttpActionContext.Request does not have CreateResponse Meth
body: <p>I am trying to create a custom AuthorizeAttribute in ASP.Net Web API to handle Basic Auth. When overriding HandleUnauthorizedRequest I find that the HttpActionContext.Request doesn't have a CreateResponse method.</p>
  
  <p>The project is MVC 4 targetting .net 4.5. I updated Web API to version 2 using nuget.</p>
  
  <pre><code>
  using System;
  using System.Net.Http.Headers;
  using System.Text;
  using System.Threading;
  using System.Web.Http;
  
  namespace BasicAuth.Security
  {
      public class BasicAuthAttribute : AuthorizeAttribute
      {
          public override void OnAuthorization(System.Web.Http.Controllers.HttpActionContext actionContext)
          {
              if (Thread.CurrentPrincipal.Identity.IsAuthenticated)
              {
                  return;
              }
  
              var authHeader = actionContext.Request.Headers.Authorization;
              if (authHeader != null)
              {
                  if (authHeader.Scheme.Equals("basic", StringComparison.OrdinalIgnoreCase) && !string.IsNullOrWhiteSpace(authHeader.Parameter))
                  {
                      var credentials = GetCredentials(authHeader);
  
                      //Handle authentication
  
                      return;
                  }
              }
  
            HandleUnauthorizedRequest(actionContext);
          }
  
          private string[] GetCredentials(AuthenticationHeaderValue authHeader)
          {
              var raw = authHeader.Parameter;
              var encoding = Encoding.ASCII;
              var credentials = encoding.GetString(Convert.FromBase64String(raw));
  
              return credentials.Split(':');
          }
  
          protected override void HandleUnauthorizedRequest(System.Web.Http.Controllers.HttpActionContext actionContext)
          {
              actionContext.Response = actionContext.Request. //No CreateResponse Method ?
          }
      }
  }
  </code></pre>
  
  <p>I am sure it must be a missing or incorrect reference somewhere, it is rather confusing though. Any help would be much appreciated.</p>
  
  <p>Thanks</p>