The best way is using Global.Asax, because you can manage all types of errors (Ajax calls/ all of unexpected Errors). with others you can’t do it.
Like this:
protected void Application_Error()
{
HttpContext httpContext = HttpContext.Current;
if (httpContext != null)
{
RequestContext requestContext = ((MvcHandler)httpContext.CurrentHandler).RequestContext;
/* When the request is ajax the system can automatically handle a mistake with a JSON response.
Then overwrites the default response */
if (requestContext.HttpContext.Request.IsAjaxRequest())
{
httpContext.Response.Clear();
string controllerName = requestContext.RouteData.GetRequiredString("controller");
IControllerFactory factory = ControllerBuilder.Current.GetControllerFactory();
IController controller = factory.CreateController(requestContext, controllerName);
ControllerContext controllerContext = new ControllerContext(requestContext, (ControllerBase)controller);
JsonResult jsonResult = new JsonResult
{
Data = new { success = false, serverError = "500" },
JsonRequestBehavior = JsonRequestBehavior.AllowGet
};
jsonResult.ExecuteResult(controllerContext);
httpContext.Response.End();
}
else
{
httpContext.Response.Redirect("~/Error");
}
}
}