单击导航药丸时，Bootstrap中的选项卡式下拉菜单一直处于关闭状态

<ul class="nav nav-pills">
  <li class="nav-item">
    <a class="nav-link active" data-toggle="pill" href="#menu1">菜单1</a>
  </li>
  <li class="nav-item">
    <a class="nav-link" data-toggle="pill" href="#menu2">菜单2</a>
  </li>
</ul>

<div class="tab-content">
  <div id="menu1" class="tab-pane fade show active">
    <ul class="dropdown-menu">
      <!-- 下拉菜单内容 -->
    </ul>
  </div>
  <div id="menu2" class="tab-pane fade">
    <ul class="dropdown-menu">
      <!-- 下拉菜单内容 -->
    </ul>
  </div>
</div>

$('.nav-link').click(function() {
  $(this).tab('show');
});

$(document).ready(function() {
  $('.nav-link').tab();
});