使用.align-content-center类在Bootstrap 4的中心对齐收集的项目。
设置align-content-center类，如下所示-
<div class="d-flex flex-wrap align-content-center bg-primary">
之后，添加弹性项目-
<div class="d-flex flex-wrap align-content-center bg-primary" style="height:250px"> <div class="p-2 border">One</div> <div class="p-2 border">Two</div> <div class="p-2 border">Three</div> </div>
让我们看一个实现align-content-center类的示例-
<!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"> <h2>Example</h2> <div class="d-flex flex-wrap align-content-center bg-primary" style="height:250px"> <div class="p-2 border">One</div> <div class="p-2 border">Two</div> <div class="p-2 border">Three</div> <div class="p-2 border">Four</div> <div class="p-2 border">Five</div> <div class="p-2 border">Six</div> <div class="p-2 border">Seven</div> <div class="p-2 border">Eight</div> <div class="p-2 border">Nine</div> <div class="p-2 border">Ten</div> <div class="p-2 border">Eleven</div> <div class="p-2 border">Twelve</div> <div class="p-2 border">Thirteen</div> <div class="p-2 border">Fourteen</div> </div> </div> </body> </html>