程序运行截图如下:

源码如下:
- <!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">
-         <button type="button" class="btn">btn按钮</button>
-         <button type="button" class="btn btn-primary">btn-primary按钮</button>
-         <button type="button" class="btn btn-secondary">btn-secondary按钮</button>
-         <button type="button" class="btn btn-success">btn-success按钮</button>
-         <button type="button" class="btn btn-info">btn-info按钮</button>
-         <button type="button" class="btn btn-warning">btn-warning按钮</button>
-         <button type="button" class="btn btn-dark">btn-dark按钮</button>
-         <button type="button" class="btn btn-light">btn-light按钮</button>
-         <button type="button" class="btn btn-link">btn-link按钮</button>
-         <br/>
-         <button type="button" class="btn">btn按钮</button>
-         <button type="button" class="btn btn-outline-primary">btn-primary按钮</button>
-         <button type="button" class="btn btn-outline-secondary">btn-secondary按钮</button>
-         <button type="button" class="btn btn-outline-success">btn-success按钮</button>
-         <button type="button" class="btn btn-outline-info">btn-info按钮</button>
-         <button type="button" class="btn btn-outline-warning">btn-warning按钮</button>
-         <button type="button" class="btn btn-outline-dark">btn-dark按钮</button>
-         <button type="button" class="btn btn-outline-light">btn-light按钮</button>
-         <button type="button" class="btn btn-outline-link">btn-link按钮</button>
-         <br/>
-         <button type="button" class="btn">btn按钮</button>
-         <button type="button" class="btn btn-outline-primary btn-lg">btn-primary按钮</button>
-         <button type="button" class="btn btn-outline-secondary btn-lg">btn-secondary按钮</button>
-         <button type="button" class="btn btn-outline-success btn-lg">btn-success按钮</button>
-         <button type="button" class="btn btn-outline-info btn-lg">btn-info按钮</button>
-         <button type="button" class="btn btn-outline-warning btn-lg">btn-warning按钮</button>
-         <button type="button" class="btn btn-outline-dark btn-lg">btn-dark按钮</button>
-         <button type="button" class="btn btn-outline-light btn-lg">btn-light按钮</button>
-         <button type="button" class="btn btn-outline-link btn-lg">btn-link按钮</button>
-         <br/>
-         <button type="button" class="btn">btn按钮</button>
-         <button type="button" class="btn btn-outline-primary btn-lg btn-block">btn-primary按钮</button>
-         <button type="button" class="btn btn-outline-secondary btn-lg btn-block">btn-secondary按钮</button>
-         <button type="button" class="btn btn-outline-success btn-lg btn-block">btn-success按钮</button>
-         <button type="button" class="btn btn-outline-info btn-lg btn-block">btn-info按钮</button>
-         <button type="button" class="btn btn-outline-warning btn-lg btn-block">btn-warning按钮</button>
-         <button type="button" class="btn btn-outline-dark btn-lg btn-block">btn-dark按钮</button>
-         <button type="button" class="btn btn-outline-light btn-lg btn-block">btn-light按钮</button>
-         <button type="button" class="btn btn-outline-link btn-lg btn-block">btn-link按钮</button>
-         <br/>
-         <button type="button" class="btn btn-outline-primary btn-lg btn-block active">btn-primary按钮</button>
-         <button type="button" class="btn btn-outline-secondary btn-lg btn-block" disabled>btn-secondary按钮</button>
-         <br/>
-         <button class="btn btn-primary">
-             <span class="spinner-border spinner-border-sm"></span>
-         </button>
-         <button class="btn btn-primary">
-             <span class="spinner-border spinner-border-sm"></span>
-             Loading...
-         </button>
-         <button class="btn btn-primary">
-             <span class="spinner-grow spinner-grow-sm"></span>
-             Loading...
-         </button>
-     </div>
- </body>
- </html>
解释:
①span中的一个类是spinner-border和sprnner-graw分别代表的效果:
②使用BootStrap的button属性时,要用btn类,后面再接各种不同的类样式。

 
                

















