Bootstrap 4：显示两行后跟阅读更多可扩展 link

Question

我正在按照 this 惊人的指南显示两行文本，并为用户提供 link 到 "Read More"。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 bootstrap 3。但由于您使用的是 bootstrap 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;
}

Fiddle

另外提醒您 ::after 是一个伪元素，因此请使用双冒号表示法

Bootstrap 4：显示两行后跟阅读更多可扩展 link

Bootstrap 4: Display two lines followed by a Read More expandable link

html

css

collapsable

bootstrap-4