如何在折叠/折叠时更改引导手风琴标题

Question

当所有面板都折叠时，背景颜色应为白色。 打开面板时，面板标题背景颜色应为灰色。 请问我该怎么做？

      <div class="panel panel-simple">
        <div class="panel-heading" role="tab" id="headingOneMaintenance">
          <h4 class="panel-title">
            <a class="accordion-toggle" role="button" data-toggle="collapse" data-parent="#accordionMaintenance" href="#collapseOneMaintenance" aria-expanded="true" aria-controls="collapseOneMaintenance">
              What will you do to prepare my apartment before I move in? 
            </a>
          </h4>
        </div>
        <div id="collapseOneMaintenance" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOneMaintenance">
          <div class="panel-body">
            Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
          </div>
        </div>
      </div>

使用此 CSS，我的所有面板都是白色的，但是当面板打开时，我希望标题为灰色：

.panel-heading {
   background-color: white;}

不过，它不一定是这个 CSS。 谢谢！

Answer 1

你可以

做一些技巧来.accordion-toggle CSS边距和填充，以覆盖所有面板尺寸：

以下代码段：

.accordion-toggle {
  background-color: gray;
  display: block;
  padding: 10px;
  margin: -10px -15px;
  border-top-left-radius: 4px;
  border-top-right-radius: 4px;
}
.accordion-toggle.collapsed {
  background-color: white;
}

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<div class="panel panel-simple">
  <div class="panel-heading" role="tab" id="headingOneMaintenance">
    <h4 class="panel-title">
      <a class="accordion-toggle" role="button" data-toggle="collapse" data-parent="#accordionMaintenance" href="#collapseOneMaintenance" aria-expanded="true" aria-controls="collapseOneMaintenance">
        What will you do to prepare my apartment before I move in?
      </a>
    </h4>
  </div>
  <div id="collapseOneMaintenance" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOneMaintenance">
    <div class="panel-body">
      Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird
      on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw
      denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
    </div>
  </div>
</div>

Answer 2

试试这段代码：

 $(document).on('click', '.panel-heading', function(){
    $('.panel-heading').css('background-color', 'grey');
    if ($(this).find('.accordion-toggle').hasClass('collapsed')) {
        $(this).css('background-color', 'white');
    }
 })

.panel-heading {
   background-color: grey;}

<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<div class="panel panel-simple">
  <div class="panel-heading" role="tab" id="headingOneMaintenance">
    <h4 class="panel-title">
      <a class="accordion-toggle" role="button" data-toggle="collapse" data-parent="#accordionMaintenance" href="#collapseOneMaintenance" aria-expanded="true" aria-controls="collapseOneMaintenance">
        What will you do to prepare my apartment before I move in? 
      </a>
    </h4>
  </div>
  <div id="collapseOneMaintenance" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOneMaintenance">
    <div class="panel-body">
      Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.
    </div>
  </div>
</div>