在Bootstrap 4中使用bg-dark上下文类为卡添加灰色背景-
在下面的代码片段中，我使用了bg-dark类来设置Bootstrap卡的样式。有了这个，我也有课文课，将文本设置为白色-
<div class="card bg-dark text-white"> <div class="card-body">This is it!</div> </div>
让我们看看使用bg-dark类的完整示例-
<!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"> <h2>Notification</h2> <div class="card bg-dark text-white"> <div class="card-body">This is it!</div> </div><br> <div class="card"> <div class="card-body">How you doing?</div> </div><br> </div> </body> </html>