MVC with Bootstrap Navbar - Set Selected Item to Active

Simplest thing to do is send a ViewBag parameter from your controllers like following;

public ActionResult About()
    {            
        ViewBag.Current = "About";
        return View();
    }


    public ActionResult Contact()
    {            
        ViewBag.Current = "Contact";
        return View();
    }

In the cshtml page do the following;

           <ul class="nav navbar-nav">                    
                <li class="@(ViewBag.Current == "About" ? "active" : "")">@Html.ActionLink("About", "About", "Home")</li>
                <li class="@(ViewBag.Current == "Contact" ? "active" : "")">@Html.ActionLink("Contact", "Contact", "Home")</li>
            </ul>

Courtesy to @Damith in here

You have to check in your controller or view which menu item is active based on the current url:

I have an extension method similar to this:

public static string MakeActiveClass(this UrlHelper urlHelper, string controller)
{
    string result = "active";

    string controllerName = urlHelper.RequestContext.RouteData.Values["controller"].ToString();

    if (!controllerName.Equals(controller, StringComparison.OrdinalIgnoreCase))
    {
        result = null;
    }

    return result;
}

You can use it in your view like this:

<!-- Make the list item active when the current controller is equal to "blog" -->
<li class="@Url.MakeActive("blog")">
   <a href="@Url.Action("index", "blog")">....</a>
</li>

The JavaScript isn't working because the page is getting reloaded after it runs. So it correctly sets the active item and then the page loads because the browser is following the link. Personally, I would remove the JavaScript you have because it serves no purpose. To do this client side (instead of the server side code you have), you need JavaScript to set the active item when the new page loads. Something like:

$(document).ready(function() {
    $('ul.nav.navbar-nav').find('a[href="' + location.pathname + '"]')
        .closest('li').addClass('active');
});

I recommend adding an id or other class to your navbar so you can be sure you have selected the correct one.