Bootstrap 4 .border-success类
在Bootstrap中的元素上显示绿色边框，以指示使用border-success类成功。
将边框设置为绿色-
<div class="mystyle border border-success"> Green border </div>
我还在div中添加了“mystyle”类，该类用于设置div的样式，在我的示例中为矩形-
.mystyle {
width: 250px;
height: 150px;
margin: 10px;
}实现边框成功，如下所示-
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>
<style>
.mystyle {
width: 250px;
height: 150px;
margin: 10px;
}
</style>
</head>
<body>
<div class="container">
<h2>Shape</h2>
<div class="mystyle border border-success">Green border</div>
</div>
</body>
</html>