要垂直显示flex项目，请使用Bootstrap 4中的flex-column类-
<div class="d-flex flex-column mb-3">
现在在其中设置弹性项目-
<div class="d-flex flex-column mb-3"> <div class="p-2 bg-info">One</div> <div class="p-2 bg-warning">Two</div> <div class="p-2 bg-info">Three</div> <div class="p-2 bg-danger">Four</div> <div class="p-2 bg-info">Five</div> </div>
让我们看一个例子来学习如何学习如何显示flex-column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 mt-3"> <h2>Example of Flex Column</h2> <p>Stating the usage of flex column class:</p> <div class="d-flex flex-column mb-3"> <div class="p-2 bg-info">One</div> <div class="p-2 bg-warning">Two</div> <div class="p-2 bg-info">Three</div> <div class="p-2 bg-danger">Four</div> <div class="p-2 bg-info">Five</div> </div> </div> </body> </html>