In MVC how can I use the controller to render a partial view only for approved users?

Question

In MVC 5 I am attempting to use the controller to render a partial view only if the (Windows Authenticated) user belongs to one or more of a list of Active Directory groups.

Answer 1

Thanks to @Stephen Muecke and and a commenter whose entry has mysteriously vanished, I have the missing pieces.

I was able to test this code with several real users and verified the desired behavior happens consistently.

Controller Block: Main difference: take out authorization and use an if-then block send one of two partial views.

[ChildActionOnly]                
    public ActionResult MonitorCSU()
    {         
        if (User.IsInRole("DOMAIN\\GroupA")) 
        {
        return PartialView("MonitorCSU");         
        }
        else 
        {
        return PartialView("Unauthorized");
            // this is an empty page
        }
    }

View Block: The key difference is using HTML.Action

@Html.Action("MonitorCSU")