helper实现隐藏前台特效

<ul class="nav nav-tabs">
        <li class="active">
             <a href="#tab_1" data-toggle="tab">
                 4 Columns
             </a>
        </li>
        <li>
             <a href="#tab_2" data-toggle="tab">
                 3 Columns
             </a>
       </li>
       <li>
             <a href="#tab_3" data-toggle="tab">
                 2 Columns
             </a>
          </li>
   </ul>

@{
  string currentText=Viewbag.Text;
}

if (model.ActivityState == ActivityState.正在进行)
{
    ViewBag.Text = "active";
}
else
{
    ViewBag.Text = "activeEnd";
}

@helper MenuItem(string currentText, string allowText)
 {
     @Html.Raw(currentText == allowText ? "active" : "")
 }

<ul class="nav nav-tabs">
    <li class="@MenuItem(currentText,"active")">
        <a href="@Url.Action("Index", "Activity", new { id=Model.Id,ActivityState=ActivityState.正在进行})">
            正在进行活动
        </a>
    </li>
    <li class="@MenuItem(currentText,"activeEnd")">
        <a href="@Url.Action("Index", "Activity", new { id = Model.Id, ActivityState = ActivityState.已结束 })">
            已结束活动
        </a>
    </li>
</ul>