javascript - Bootstrap 模态标题未显示 -::before::after

Question

当我输入 $('#MesageModal').modal('show'); 时，模式的标题具有 ::before 和 ::after 周围的选择器使标题看起来很奇怪。谁能告诉我为什么会这样？

<div class="modal fade" id="MessageModal" style="display: none">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header>
        <h4 class="modal-title"></h4>
      </div>
      <div class="modal-body">
      </div>
      <div class="modal-footer">
      </div>
    </div>  
  </div>
</div>    

Answer 1

$('#MesageModal').modal('show');

应该是

$('#MessageModal').modal('show');