public override string BuildAccordionMenu(HtmlHelper helper, IMenuItem currentItem) { if (!IsVisibleInCrumb) { return(null); } IDictionary <string, string> htmlAttributes = new Dictionary <string, string>(); string cssClass = GetSubMenuCssClass(); if (cssClass.Length > 0) { htmlAttributes.Add(HtmlAttributesClassKey, cssClass.TrimEnd()); } var selected = this == currentItem.GetSelectedMenuItem() ? "class=\"" + CssSelected + "\"" : ""; return ("<li " + selected + ">" + helper.ActionLinkSpan(Title, Action, Controller, RouteValues, htmlAttributes) + (HasChildren() ? base.BuildAccordionMenu(helper, currentItem) : "") + "</li>"); }