C'# Checking if an Ajax call c# side

Question

I have some code below so that when a user calls a method in an mvc controller it does some checks to see if it is an Ajax call or not. If Ajax it returns a json response else it returns a url string (Security page). When I run in visual studio the code works perfectly so it recognises the call is an ajax call but on a production server variable "isAjax" is set to false. Is there any reason why it would work locally in visual (local iis) but not on a server?

var isAjax = (filterContext.RequestContext.HttpContext.Request["X-Requested-With"] == "XMLHttpRequest") ||
                             ((filterContext.RequestContext.HttpContext.Request.Headers != null) &&
                             (filterContext.RequestContext.HttpContext.Request.Headers["X-Requested-With"] == "XMLHttpRequest"));

On the.network tab in the browser it shows that it is being passed (image below)

Network tab

Answer 1

public ActionResult GetData()
{
  if(Request.IsAjaxRequest())
        return RedirectToAction("AjaxRequest");
  else
        return RedirectToAction("NonAjaxRequest");
}

Instead of checking the headers you can check the current request at controller level.

Answer 2

AJAX calls will have a header named X-Requested-With , and the value will be XMLHttpRequest . So you can check like this:

bool isAjaxRequest = request.Headers["X-Requested-With"] == "XMLHttpRequest";

Otherwise you can use the System.Web.MVC reference and use the function.

bool isAjaxRequest = Request.IsAjaxRequest();