隐藏导航按钮的Bootstrap轮播问题

Question

我有这个代码，它是一个bootstrap轮播，我希望它在我悬停“#caroussel”时显示类“.carousel-indicators”（导航按钮）。

为此，我确实添加了一些不透明度参数，所以当我悬停“#caroussel”时，它将从0传递到1以便可见，这暂时不起作用。

body {
  margin: 0;
}

.carousel-indicators li {
  width: 20px;
  height: 20px;
  border-radius: 100%;
  border: 3px solid white;
  color: grey;
}

.carousel-indicators .active {
  width: 20px;
  height: 20px;
  border-radius: 100%;
  border: 3px solid black;
}

.carousel-indicators {
  opacity: 0;
}

#caroussel:hover,
#caroussel:hover~.carousel-indicators {
  opacity: 1;
}

<!--BS CSS-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous">

<!--BS JS-->
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.3/umd/popper.min.js" integrity="sha384-ZMP7rVo3mIykV+2+9J3UJ46jBk0WLaUAdn689aCwoqbBJiSnjAK/l8WvCWPIPm49" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>


<div id="caroussel">
  <div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">

    <ol class="carousel-indicators">
      <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
      <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
      <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
    </ol>

    <div class="carousel-inner">
      <div class="carousel-item active">
        <img class="d-block w-100" src="https://fyf.tac-cdn.net/images/products/large/BF116-11KM.jpg" alt="First slide">
      </div>
      <div class="carousel-item">
        <img class="d-block w-100" src="https://04dc27fa9cbd58cbea8c-bbb0d8e518ac050fae1d74ee0f9c6cec.ssl.cf4.rackcdn.com/images/products/340x397/29.jpg" alt="Second slide">
      </div>
      <div class="carousel-item">
        <img class="d-block w-100" src="https://cdn.bloomnation.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/2/0/20140701073819_file_53b30e2b2de3f_56.jpeg" alt="Third slide">
      </div>
    </div>
    <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
      <span class="carousel-control-prev-icon" aria-hidden="true"></span>
      <span class="sr-only">Previous</span>
    </a>
    <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
      <span class="carousel-control-next-icon" aria-hidden="true"></span>
      <span class="sr-only">Next</span>
    </a>
  </div>
</div>

感谢大家。

Answer 1

你使用了错误的选择器; ~是general sibling selector。由于.carousel-indicators是#caroussel的子元素，这应该是你需要的所有（使用descendant selector）：

#caroussel:hover .carousel-indicators
{ 
    opacity: 1;
}

Answer 2

试试这个代码。

.carousel-indicators {
    -webkit-transition: all 0.5s linear;
    -moz-transition: all 0.5s linear;
    -ms-transition: all 0.5s linear;
    -o-transition: all 0.5s linear;
    transition: all 0.5s linear;
    opacity: 0;
}
#carousel:hover .carousel-indicators {
    opacity: 1;
}