笔记：Bootstrap4 按钮组

Bootstrap4 按钮组允许将按钮放在同一行上。

可以在 <div> 元素上添加 .btn-group 类来创建按钮组。

<div class="btn-group">

  <button type="button" class="btn btn-primary">Apple</button>

  <button type="button" class="btn btn-primary">Samsung</button>

  <button type="button" class="btn btn-primary">Sony</button>

</div>

可以使用 .btn-group-lg|sm 类来设置按钮组的大小。

<div class="btn-group btn-group-lg">

  <button type="button" class="btn btn-primary">Apple</button>

  <button type="button" class="btn btn-primary">Samsung</button>

  <button type="button" class="btn btn-primary">Sony</button>

</div>

可以使用 .btn-group-vertical 类来创建垂直的按钮组：

<div class="btn-group-vertical">

  <button type="button" class="btn btn-primary">Apple</button>

  <button type="button" class="btn btn-primary">Samsung</button>

  <button type="button" class="btn btn-primary">Sony</button>

</div>

可以在按钮组内设置下拉菜单：

<div class="btn-group">

  <button type="button" class="btn btn-primary">Apple</button>

  <button type="button" class="btn btn-primary">Samsung</button>

  <div class="btn-group">

    <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">

      Sony

    </button>

    <div class="dropdown-menu">

      <a class="dropdown-item" href="#">Tablet</a>

      <a class="dropdown-item" href="#">Smartphone</a>

    </div>

  </div>

</div>

拆分按钮下拉菜单

<div class="btn-group">

  <button type="button" class="btn btn-primary">Sony</button>

  <button type="button" class="btn btn-primary dropdown-toggle dropdown-toggle-split" data-toggle="dropdown">

    <span class="caret"></span>

  </button>

  <div class="dropdown-menu">

    <a class="dropdown-item" href="#">Tablet</a>

    <a class="dropdown-item" href="#">Smartphone</a>

  </div>

</div>

垂直按钮组及下拉菜单

<div class="btn-group-vertical">

  <button type="button" class="btn btn-primary">Apple</button>

  <button type="button" class="btn btn-primary">Samsung</button>

  <div class="btn-group">

    <button type="button" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">

      Sony

    </button>

    <div class="dropdown-menu">

      <a class="dropdown-item" href="#">Tablet</a>

      <a class="dropdown-item" href="#">Smartphone</a>

    </div>

  </div>

</div>