bootstrap4这个页面前面已经加载了官方的bootstrap4的CDN的这四个文件
<link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/4.0.0-beta/css/bootstrap.min.css"> <script src="https://cdn.bootcss.com/bootstrap/4.0.0-beta/js/bootstrap.min.js" ></script> <script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.slim.min.js"></script> <script src="https://cdn.bootcss.com/popper.js/1.12.3/umd/popper.min.js"></script>
然后带入组件:可版本要是换成3.3.7的就正常了,不知道是哪里出现了问题(求bootstrap4的大神指点1,2)
<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" role="listbox"> <div class="carousel-item active"> <img class="d-block img-fluid" src="./images/1.jpg" alt="First slide"> </div> <div class="carousel-item"> <img class="d-block img-fluid" src="./images/ribbon.png" alt="Second slide"> </div> <div class="carousel-item"> <img class="d-block img-fluid" src="./images/2016.png" 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>
可能是 引用js、css顺序错误,必须css、然后是jquery.js,最后再是bootstrap.js,可以参考下面这篇
http://www.dodblog.cn/index.php/2020/05/06/bootstrap%e8%bd%ae%e6%92%ad%e5%9b%be%e6%97%a0%e6%b3%95%e5%88%87%e6%8d%a2%e7%9a%84%e8%a7%a3%e5%86%b3%e6%96%b9%e6%b3%95/