MVC display UserName on layout page - model-view-controller

Question

In my app, users can login via a barcode scan.
The scan triggers a controller action like so:
function scanner(value) {
var badge = (value.startsWith('B-') || value.startsWith('B-')); //b- of B- = badge scan
if (badge)
{
$.ajax({
type: 'GET',
url: '/Login/Login',
data: {'badge': value},
succes: function () {
console.log("logged in");
}
});
}
else return;
}
Controller action:
public ActionResult Login(string badge)
{
string userName = string.Empty;
if (badge != null)
{
int oncid;
if (Int32.TryParse(badge.Substring(2), out oncid))
{
Core.Employee employee = Data.Oracle.GetEmployee(oncid.ToString());
if (employee != null)
{
userName = employee.FirstName + ' ' + employee.Name;
}
}
else
userName = "invalid badge";
}
ViewBag.UserName = userName;
return PartialView("_Login");
}
in _Layout.cshtml:
<nav class="navbar fixed-top navbar-expand-sm navbar-dark bg-dark">
<div class="container">
<a class="navbar-brand" href="#"><img src="~/Content/Images/logo.png" height="36" width="36" class="d-inline-block align-top"> App Name</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation"><span class="navbar-toggler-icon"></span></button>
<div class="collapse navbar-collapse" id="navbarNav">
<ul class="navbar-nav ml-auto mt-2 mt-lg-0">
<li class="nav-item active">
#*<a class="nav-link" href="#Url.Action("Index", "Home")">Home <span class="sr-only">(current)</span></a>*#
<a class="nav-link" href="#Url.Action("Index", "Home")"><span class="fas fa-home fa-2x" aria-hidden="true"></span></a>
</li>
<li class="nav-item">
<a class="nav-link" id="smrButton" href="#">SMR</a>
</li>
</ul>
</div>
#Html.Partial("_Login")
</div>
</nav>
_Login.cshtml just has #ViewBag.UserName for now.
If i set a breakpoint here, i can see that ViewBag.UserName holds the correct value, however, nothing is displayed in my page layout. What am i missing here?

Answer 1

Try using Session instead of ViewBag. For example:
Session["username"] = userName;
And call it in the view, simple as that