自学教程Bootstrap 4 提供了不同样式的按钮。
<button type="button" class="btn">基本按钮</button>
<button type="button" class="btn btn-primary">主要按钮</button>
<button type="button" class="btn btn-secondary">次要按钮</button>
<button type="button" class="btn btn-success">成功</button>
<button type="button" class="btn btn-info">信息</button>
<button type="button" class="btn btn-warning">警告</button>
<button type="button" class="btn btn-danger">危险</button>
<button type="button" class="btn btn-dark">黑色</button>
<button type="button" class="btn btn-light">浅色</button>
<button type="button" class="btn btn-link">链接</button>按钮类可用于 <a>, <button>, 或 <input> 元素上:
<a href="#" class="btn btn-info" role="button">链接按钮</a>
<button type="button" class="btn btn-info">按钮</button>
<input type="button" class="btn btn-info" value="输入框按钮">
<input type="submit" class="btn btn-info" value="提交按钮">按钮设置边框
<button type="button" class="btn btn-outline-primary">主要按钮</button>
<button type="button" class="btn btn-outline-secondary">次要按钮</button>
<button type="button" class="btn btn-outline-success">成功</button>
<button type="button" class="btn btn-outline-info">信息</button>
<button type="button" class="btn btn-outline-warning">警告</button>
<button type="button" class="btn btn-outline-danger">危险</button>
<button type="button" class="btn btn-outline-dark">黑色</button>
<button type="button" class="btn btn-outline-light text-dark">浅色</button>不同大小的按钮
Bootstrap 4 可以设置按钮的大小：
<button type="button" class="btn btn-primary btn-lg">大号按钮</button>
<button type="button" class="btn btn-primary">默认按钮</button>
<button type="button" class="btn btn-primary btn-sm">小号按钮</button>块级按钮
通过添加 .btn-block 类可以设置块级按钮：
<button type="button" class="btn btn-primary btn-block">按钮 1</button>
激活和禁用的按钮
按钮可设置为激活或者禁止点击的状态。
.active 类可以设置按钮是可用的， disabled 属性可以设置按钮是不可点击的。 注意 <a> 元素不支持 disabled 属性，你可以通过添加 .disabled 类来禁止链接的点击。
<button type="button" class="btn btn-primary active">点击后的按钮</button>
<button type="button" class="btn btn-primary" disabled>禁止点击的按钮</button>
<a href="#" class="btn btn-primary disabled">禁止点击的链接</a>加载按钮
我们也可以设置一个正在加载的按钮。
<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" disabled>
<span class="spinner-border spinner-border-sm"></span>
Loading..
</button>
<button class="btn btn-primary" disabled>
<span class="spinner-grow spinner-grow-sm"></span>
Loading..
</button>