Ajax AntiForgery不会验证

Question

一个可爱的属性......

public class GlobalAntiForgeryTokenAttribute : FilterAttribute, IAuthorizationFilter
    {
        public void OnAuthorization(AuthorizationContext filterContext)
        {
            var request = filterContext.HttpContext.Request;

            if (request.HttpMethod == WebRequestMethods.Http.Post)
            {
                var token = request.Headers["__RequestVerificationToken"];

                if (string.IsNullOrEmpty(token))
                {
                    AntiForgery.Validate();
                }
                else
                {
                    var antiForgeryCookie = request.Cookies[AntiForgeryConfig.CookieName];

                    var cookieValue = antiForgeryCookie == null
                        ? null
                        : antiForgeryCookie.Value;

                    AntiForgery.Validate(cookieValue, token);
                }
            }
        }
    }

Angular $ http post ...

$http.post('', this.data, {
                headers: {
                    '__RequestVerificationToken':
                        $('input[name="__RequestVerificationToken"]').val()
                }
            }).success(function (data, status, headers) {
                    console.log(data);
            });

然后在HTML ..

@Html.AntiForgeryToken()

浏览器中的cookie值与预期值一样，是隐藏字段的值，但它们不会验证。

为什么不呢？