Toast notifications in ASP.NET MVC 4

Answer 1:

<script type="text/javascript">
    $(document).ready(function () { 
       if('@TempData["message"]' == "Added"){
          toastr.success('Added');
       }
       else{ }
    });
</script> 

Answer 2:

Although TempData retain its value on one redirect but sometimes it creates problem(and it is recommended to avoid using TempData) in that case you can do as:

public ActionResult AddToCart(int id)
{
    .........
    return RedirectToAction("Index", new { message="Added" });  //Send Object Route//
}

public ActionResult Index(string message)
{
    .........
    if(!string.IsNullOrEmpty(message)) {
       Viewbag.message=message;
    }
    return View();
}

<script type="text/javascript">
    $(document).ready(function () { 
       if('@Viewbag.message' == "Added") {
          toastr.success('Added');
       }
       else{ }
    });
</script>