程序运行截图如下:

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">
-         <img src="pic/it1995.jpg" />
-         <img src="pic/it1995.jpg" class="rounded" />
-         <img src="pic/it1995.jpg" class="rounded-circle" />
-         <img src="pic/it1995.jpg" class="img-thumbnail" />
-         <img src="pic/it1995.jpg" class="float-right" />
-         <img src="pic/it1995.jpg" class="mx-auto d-block" />
-         <img src="pic/it1995.jpg" class="img-fluid" />
-     </div>
- </body>
- </html>
解释:这里关键就是配置对应class即可。

 
                

















