[asp.net-mvc-3] Proper way to use AJAX Post in jquery to pass model from strongly typed MVC3 view

If using MVC 5 read this solution!

I know the question specifically called for MVC 3, but I stumbled upon this page with MVC 5 and wanted to post a solution for anyone else in my situation. I tried the above solutions, but they did not work for me, the Action Filter was never reached and I couldn't figure out why. I am using version 5 in my project and ended up with the following action filter:

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

namespace SydHeller.Filters
{
    public class ValidateJSONAntiForgeryHeader : FilterAttribute, IAuthorizationFilter
    {
        public void OnAuthorization(AuthorizationContext filterContext)
        {
            string clientToken = filterContext.RequestContext.HttpContext.Request.Headers.Get(KEY_NAME);
            if (clientToken == null)
            {
                throw new HttpAntiForgeryException(string.Format("Header does not contain {0}", KEY_NAME));
            }

            string serverToken = filterContext.HttpContext.Request.Cookies.Get(KEY_NAME).Value;
            if (serverToken == null)
            {
                throw new HttpAntiForgeryException(string.Format("Cookies does not contain {0}", KEY_NAME));
            }

            System.Web.Helpers.AntiForgery.Validate(serverToken, clientToken);
        }

        private const string KEY_NAME = "__RequestVerificationToken";
    }
}

-- Make note of the using System.Web.Mvc and using System.Web.Mvc.Filters, not the http libraries (I think that is one of the things that changed with MVC v5. --

Then just apply the filter [ValidateJSONAntiForgeryHeader] to your action (or controller) and it should get called correctly.

In my layout page right above </body> I have @AntiForgery.GetHtml();

Finally, in my Razor page, I do the ajax call as follows:

var formForgeryToken = $('input[name="__RequestVerificationToken"]').val();

$.ajax({
  type: "POST",
  url: serviceURL,
  contentType: "application/json; charset=utf-8",
  dataType: "json",
  data: requestData,
  headers: {
     "__RequestVerificationToken": formForgeryToken
  },
     success: crimeDataSuccessFunc,
     error: crimeDataErrorFunc
});