使用Bootstrap 4在特定的屏幕宽度上创建一个块元素
要在特定的屏幕宽度上创建块，请使用.d-*-block类。
特定的屏幕宽度可以是小，中，大和特大。根据屏幕尺寸分别设置类，如下所示-
<span class="d-sm-block bg-primary"> d-sm-block </span> <span class="d-md-block bg-success"> d-md-block </span> <span class="d-lg-block bg-info"> d-lg-block< /span> <span class="d-xl-block bg-warning"> d-xl-block </span>
让我们看完整的示例，以学习如何在特定的屏幕宽度上创建一个块元素-
示例
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container mt-3">
<h2>Blocks</h2>
<p>Resize the browser to check the effect</p>
<span class="d-block bg-info">d-block</span>
<span class="d-sm-block bg-primary">d-sm-block</span>
<span class="d-md-block bg-success">d-md-block</span>
<span class="d-lg-block bg-info">d-lg-block</span>
<span class="d-xl-block bg-warning">d-xl-block</span>
</div>
</body>
</html>