使用Bootstrap 4在不同的屏幕上将项目弯曲成相等的宽度
要将flex项目在不同屏幕上设置为相等的宽度，请使用flex-*-fill类。
对于小宽度的屏幕，请使用flex-sm-fill-
<div class="p-2 flex-sm-fill bg-info"> A </div>
对于大宽度的屏幕，请使用flex-lg-fill-
<div class="p-2 flex-lg-fill bg-info"> A </div>
以下是为不同屏幕上的伸缩项目提供euqla宽度的示例-
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 (Small Width)</h3>
<div class="d-flex mb-3 bg-primary">
<div class="p-2 flex-sm-fill bg-info">A</div>
<div class="p-2 flex-sm-fill bg-warning">B</div>
<div class="p-2 flex-sm-fill bg-primary">C</div>
</div>
<h3>Flex (Medium Width)</h3>
<div class="d-flex mb-3 bg-primary">
<div class="p-2 flex-md-fill bg-info">A</div>
<div class="p-2 flex-md-fill bg-warning">B</div>
<div class="p-2 flex-md-fill bg-primary">C</div>
</div>
<h3>Flex (Large Width)</h3>
<div class="d-flex mb-3 bg-primary">
<div class="p-2 flex-lg-fill bg-info">A</div>
<div class="p-2 flex-lg-fill bg-warning">B</div>
<div class="p-2 flex-lg-fill bg-primary">C</div>
</div>
</div>
</body>
</html>