允许将弹性项目包装在不同屏幕上的Bootstrap中
要允许将flex项目包装在不同的屏幕上，请使用flex-*-wrap类。适用于各种屏幕尺寸的柔性包装适用于小，中，大和超大屏幕。
例如，使用flex-lg-wrap类在大屏幕上包装flex项目-
<div class="d-flex flex-lg-wrap bg-primary">
对于小屏幕-
<div class="d-flex flex-sm-wrap bg-primary">
您可以尝试运行以下代码来实现flex-*-wrap类，以在小屏幕和大屏幕尺寸上包装flex项目-
示例
<!DOCTYPE html>
<html lang="en">
<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">
<h3>Flex Examples</h3>
<p>Wrap - Yes</p>
<div class="d-flex flex-wrap bg-primary">
<div class="p-2 border">Poland</div>
<div class="p-2 border">Netherlands</div>
<div class="p-2 border">Ireland</div>
<div class="p-2 border">Brazil</div>
<div class="p-2 border">India</div>
<div class="p-2 border">US</div>
<div class="p-2 border">Bangladesh</div>
<div class="p-2 border">Russia</div>
<div class="p-2 border">Morocco</div>
<div class="p-2 border">UK</div>
<div class="p-2 border">Australia</div>
<div class="p-2 border">Denmark</div>
</div>
<br>
<p>Will wrap on Small Screen</p>
<div class="d-flex flex-sm-wrap bg-primary">
<div class="p-2 border">Poland</div>
<div class="p-2 border">Netherlands</div>
<div class="p-2 border">Ireland</div>
<div class="p-2 border">Brazil</div>
<div class="p-2 border">India</div>
<div class="p-2 border">US</div>
<div class="p-2 border">Bangladesh</div>
<div class="p-2 border">Russia</div>
<div class="p-2 border">Morocco</div>
<div class="p-2 border">UK</div>
<div class="p-2 border">Australia</div>
<div class="p-2 border">Denmark</div>
</div><br>
<p>Will Wrap on Large Screen</p>
<div class="d-flex flex-lg-wrap bg-primary">
<div class="p-2 border">Poland</div>
<div class="p-2 border">Netherlands</div>
<div class="p-2 border">Ireland</div>
<div class="p-2 border">Brazil</div>
<div class="p-2 border">India</div>
<div class="p-2 border">US</div>
<div class="p-2 border">Bangladesh</div>
<div class="p-2 border">Russia</div>
<div class="p-2 border">Morocco</div>
<div class="p-2 border">UK</div>
<div class="p-2 border">Australia</div>
<div class="p-2 border">Denmark</div>
</div><br>
</div>
</body>
</html>