程序运行截图:

代码如下:
- <!DOCTYPE html>
- <html lang="en">
- <head>
-     <meta charset="UTF-8">
-     <title>CN_TEST1</title>
-     <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
-  
- <!--    bootstrap css核心文件-->
-     <link rel="stylesheet" href="bootstrap-4.4.1-dist/css/bootstrap.min.css">
- <!--    bootstrap使用到了jquery,需要提前引用-->
-     <script src="js/jquery-3.5.1.min.js"></script>
- <!--    弹窗、提示、下拉菜单-->
-     <script src="bootstrap-4.4.1-dist/js/bootstrap.bundle.js"></script>
- <!--    bootstrap核心文件-->
-     <script src="bootstrap-4.4.1-dist/js/bootstrap.min.js"></script>
-  
- </head>
- <body>
-  
-     <div class="container-fluid">
-  
-         <ul class="pagination">
-             <li class="page-item"><a class="page-link" href="#">Previous</a></li>
-             <li class="page-item"><a class="page-link" href="#">1</a></li>
-             <li class="page-item"><a class="page-link" href="#">2</a></li>
-             <li class="page-item"><a class="page-link" href="#">3</a></li>
-             <li class="page-item"><a class="page-link" href="#">4</a></li>
-             <li class="page-item"><a class="page-link" href="#">Next</a></li>
-         </ul>
-  
-         <br/>
-  
-         <ul class="pagination">
-             <li class="page-item"><a class="page-link" href="#">Previous</a></li>
-             <li class="page-item"><a class="page-link" href="#">1</a></li>
-             <li class="page-item"><a class="page-link" href="#">2</a></li>
-             <li class="page-item active"><a class="page-link" href="#">3</a></li>
-             <li class="page-item"><a class="page-link" href="#">4</a></li>
-             <li class="page-item"><a class="page-link" href="#">Next</a></li>
-         </ul>
-  
-         <br/>
-  
-         <ul class="pagination">
-             <li class="page-item disabled"><a class="page-link" href="#">Previous</a></li>
-             <li class="page-item"><a class="page-link" href="#">1</a></li>
-             <li class="page-item"><a class="page-link" href="#">2</a></li>
-             <li class="page-item active"><a class="page-link" href="#">3</a></li>
-             <li class="page-item"><a class="page-link" href="#">4</a></li>
-             <li class="page-item"><a class="page-link" href="#">Next</a></li>
-         </ul>
-  
-         <br/>
-  
-         <ul class="pagination pagination-lg">
-             <li class="page-item"><a class="page-link" href="#">Previous</a></li>
-             <li class="page-item"><a class="page-link" href="#">1</a></li>
-             <li class="page-item"><a class="page-link" href="#">2</a></li>
-             <li class="page-item active"><a class="page-link" href="#">3</a></li>
-             <li class="page-item"><a class="page-link" href="#">4</a></li>
-             <li class="page-item"><a class="page-link" href="#">Next</a></li>
-         </ul>
-  
-         <br/>
-  
-         <ul class="pagination pagination-sm">
-             <li class="page-item"><a class="page-link" href="#">Previous</a></li>
-             <li class="page-item"><a class="page-link" href="#">1</a></li>
-             <li class="page-item"><a class="page-link" href="#">2</a></li>
-             <li class="page-item active"><a class="page-link" href="#">3</a></li>
-             <li class="page-item"><a class="page-link" href="#">4</a></li>
-             <li class="page-item"><a class="page-link" href="#">Next</a></li>
-         </ul>
-  
-         <br/>
-  
-         <ul class="breadcrumb">
-             <li class="breadcrumb-item"><a href="#">Photos</a></li>
-             <li class="breadcrumb-item"><a href="#">Summer 2017</a></li>
-             <li class="breadcrumb-item"><a href="#">Italy</a></li>
-             <li class="breadcrumb-item active">Rome</li>
-         </ul>
-  
- <!--        默认-左对齐-->
-         <ul class="pagination" style="margin: 20px 0">
-             <li class="breadcrumb-item"><a href="#">Photos</a></li>
-             <li class="breadcrumb-item"><a href="#">Summer 2017</a></li>
-             <li class="breadcrumb-item"><a href="#">Italy</a></li>
-             <li class="breadcrumb-item active">Rome</li>
-         </ul>
-  
- <!--        居中-->
-         <ul class="pagination justify-content-center" style="margin: 20px 0">
-             <li class="breadcrumb-item"><a href="#">Photos</a></li>
-             <li class="breadcrumb-item"><a href="#">Summer 2017</a></li>
-             <li class="breadcrumb-item"><a href="#">Italy</a></li>
-             <li class="breadcrumb-item active">Rome</li>
-         </ul>
-  
-  
- <!--        右对齐-->
-         <ul class="pagination justify-content-end" style="margin: 20px 0">
-             <li class="breadcrumb-item"><a href="#">Photos</a></li>
-             <li class="breadcrumb-item"><a href="#">Summer 2017</a></li>
-             <li class="breadcrumb-item"><a href="#">Italy</a></li>
-             <li class="breadcrumb-item active">Rome</li>
-         </ul>
-  
-         <br/>
-  
-     </div>
-  
- </body>
- </html>
解释:
①在ul上添加pagination类后,就可以实现分页了;在li上添加page-item;

 
                

















