Bootstrap 4：显示两行，后跟一个 Read More 可扩展链接

Question

我正在按照这个惊人的指南显示两行文本，并为用户提供“阅读更多”的链接。转换未按预期工作。有人可以指出我在这里做错了什么吗？

#module {
  font-size: 1rem;
  line-height: 1.5;
}

#module p.collapse[aria-expanded="false"] {
  display: block;
  height: 3rem !important;
  overflow: hidden;
}

#module p.collapse.show[aria-expanded="false"] {
  height: 3rem !important;
}

#module a.collapsed:after {
  content: '+ Show More';
}

#module a:not(.collapsed):after {
  content: '- Show Less';
}

<div id="module" class="container">
  <h3>Bacon Ipsum</h3>
  <p class="collapse" id="collapseExample" aria-expanded="false">
    Bacon ipsum dolor amet doner picanha tri-tip biltong leberkas salami meatball tongue filet mignon landjaeger tail. Kielbasa salami tenderloin picanha spare ribs, beef ribs strip steak jerky cow. Pork chop chicken ham hock beef ribs turkey jerky. Shoulder
    beef capicola doner, tongue tail sausage short ribs andouille. Rump frankfurter landjaeger t-bone, kielbasa doner ham hock shankle venison. Cupim capicola kielbasa t-bone, ball tip chicken andouille venison pork chop doner bacon beef ribs kevin shankle.
    Short loin leberkas tenderloin ground round shank, brisket strip steak ham hock ham.
  </p>
  <a role="button" class="collapsed" data-toggle="collapse" href="#collapseExample" aria-expanded="false" aria-controls="collapseExample">
  </a>
</div>

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>

Answer 1

您的代码可能适用于引导程序 3。但由于您使用的是引导程序 4，请尝试以下操作。

替换这个

#module p.collapse[aria-expanded="false"] {
  display: block;
  height: 3rem !important;
  overflow: hidden;
}

#module p.collapse.show[aria-expanded="false"] {
  height: 3rem !important;
}

有了这个

#module #collapseExample.collapse:not(.show) {
  display: block;
  height: 3rem;
  overflow: hidden;
}

#module #collapseExample.collapsing {
  height: 3rem;
}

小提琴

也只是提醒您这::after是一个伪元素，因此请使用双冒号表示法