System.Web.Mvc.HtmlHelperExtension.MenuItem C# (CSharp) Method

        public static string MenuItem(this HtmlHelper helper, string linkText, string actionName, string controllerName)
        {
            string currentControllerName = (string)helper.ViewContext.RouteData.Values["controller"];
              string currentActionName = (string)helper.ViewContext.RouteData.Values["action"];

              var sb = new StringBuilder();

              if (currentControllerName.Equals(controllerName, StringComparison.CurrentCultureIgnoreCase) && currentActionName.Equals(actionName, StringComparison.CurrentCultureIgnoreCase))
            sb.Append("<li class=\"selected\">");
              else
            sb.Append("<li>");

              sb.Append(helper.ActionLink(linkText, actionName, controllerName));
              sb.Append("</li>");
              return sb.ToString();
        }