我正在尝试使用 bootstrap 4 边框为 div 提供边框。只有边框属性看起来很奇怪，而其他属性没有边框显示。请在下面找到代码片段。
我也尝试过 beta 2 版本。
如果我遗漏了什么，请告诉我。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Home</title>
<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/1.12.3/umd/popper.min.js" integrity="sha384-vFJXuSJphROIrBnz7yo7oB41mKfc8JzQZiCq4NCceLEaO4IHwicKwpJf9c9IpFgh" crossorigin="anonymous"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css" integrity="sha384-PsH8R72JQ3SOdhVi3uxftmaW6Vc51MKb0q5P2rRUpPvrszuE4W1povHYgTpBfshb" crossorigin="anonymous">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js" integrity="sha384-alpBpkh1PFOepccYVYDB4do5UnbKysX5WZXm3XxPqe5iKTfUKjNkCk9SaVuEZflJ" crossorigin="anonymous"></script>
</head>
<body>
<!-- Just created a contianer to test the border class -->
<div class="container">
<div class="text-center">
<h1> Testing bootstrap 4</h1>
</div>
<div class="row mt-2">
<div class="col-12">
<!-- Testing span with class border -->
<span class="border">
<div class="text-primary">Testing Bootsrap 4 Border </div>
</span>
</div>
</div>
<div class="row mt-2">
<div class="col-12">
<span class="border-0">Testing Bootsrap 4 Border 0</span>
</div>
</div>
<div class="row mt-2">
<div class="col-12">
<span class="border-top-0">Testing Bootsrap 4 Border top 0</span>
</div>
</div>
<div class="row mt-2">
<div class="col-12">
<span class="border-right-0">Testing Bootsrap 4 Border right 0</span>
</div>
</div>
<div class="row mt-2">
<div class="col-sm-12">
<span class="border border-light">testing border light</span>
</div>
<div class="col-sm-12"> col 2</div>
</div>
</div>
</body>
</html>最佳答案
要使 bootstrap 边框正常工作，您必须添加 border类(class)。例如，当您写 <span class="border-right-0"> 时它表明右边不应有任何边界。您还没有声明开始的边界，因此不会显示任何边界。您需要做的是<span class="border border-right-0"> .
关于html - Bootstrap 4 边框类不适用于顶部，对，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47102755/