angular - 将 Chevron 图标添加到 ngx-bootstrap Accordion

Question

单击 Accordion 时，我无法将人字形从 UP 更改为 DOWN。无论我尝试什么技巧，甚至尝试像这样的其他示例，它似乎总是结果为真 https://stackblitz.com/edit/ngx-bootstrap-ifmpph?file=app%2Fapp.component.html

        <accordion [closeOthers]="true">
                <accordion-group #group [isOpen]='true'>
                    <div accordion-heading class="clearfix">
                        Basic Information
                        <span class="badge badge-secondary float-right pull-right">
                            <i class="fa" [ngClass]="!group?.isOpen ? 'fa-chevron-down': 'fa-chevron-down'"></i>
                        </span>
                    </div>
                </accordion-group>
            </accordion>

Answer 1

这个有效:

  <accordion>
      <accordion-group #group1 [isOpen]='true'>
        <div accordion-heading class="clearfix">
        Basic Information
          <span class="badge badge-secondary float-right pull-right">
            <i class="fa" [ngClass]="{'fa-chevron-up': group1.isOpen, 'fa-chevron-down': !group1.isOpen}"></i>
          </span>
        </div>
  </accordion>