Bootstrap 4使用btn-outline-primary类设置蓝色轮廓按钮。
使用btn-outline-primary类向按钮添加蓝色轮廓，如以下代码片段所示-
<button type="button" class="btn btn-outline-primary"> Result </button>
您可以尝试运行以下代码以实现btn-outline-primary类-
<!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"> <h4>Result</h4> <p>Click below to get the result:</p> <button type="button" class="btn btn-outline-primary">Result</button> </div> </body> </html>