How to redirect from OnActionExecuting in Base Controller?

 public override void OnActionExecuting(ActionExecutingContext filterContext)
 {
    ...
    if (needToRedirect)
    {
       ...
       filterContext.Result = new RedirectResult(url);
       return;
    }
    ...
 }

It can be done this way as well:

filterContext.Result = new RedirectToRouteResult(
    new RouteValueDictionary
    {
        {"controller", "Home"},
        {"action", "Index"}
    }
);