多选/单选(Checks & radios)
使用我们完全重写的检查组件,创建一致的跨浏览器和跨设备复选框和单选框。
方法
浏览器默认的复选框和单选框在 .form-check
的帮助下被替换,这两种输入类型的一系列类改进了其 HTML 元素的布局和行为,提供了更好的自定义和跨浏览器一致性。复选框用于在列表中选择一个或多个选项,而单选用于从多个选项中选择一个。
在结构上,我们的input
和label
是兄弟元素,而不是label
中的input
。由于必须指定id和属性才能将input
和label
关联起来,因此这会稍微详细一些。我们对所有input
状态使用同级选择器(~
),例如:checked
或:disabled
。当与.form-check-label
类结合使用时,我们可以根据input
的状态轻松地为每个项设置文本样式。
我们的校验使用自定义的 Bootstrap 图标来表示选中或不确定状态。
复选框
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="flexCheckDefault">
<label class="form-check-label" for="flexCheckDefault">
Default checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="flexCheckChecked" checked>
<label class="form-check-label" for="flexCheckChecked">
Checked checkbox
</label>
</div>
不确定
通过 JavaScript 手动设置时,复选框可以使用:indeterminate
伪类(没有可用的 HTML 属性来指定它)。
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="flexCheckIndeterminate">
<label class="form-check-label" for="flexCheckIndeterminate">
Indeterminate checkbox
</label>
</div>
复选框禁用
添加 disabled
属性后,相关的<label>
会自动调整样式,用更浅的颜色来帮助显示输入的状态。
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="flexCheckIndeterminateDisabled" disabled>
<label class="form-check-label" for="flexCheckIndeterminateDisabled">
Disabled indeterminate checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="flexCheckDisabled" disabled>
<label class="form-check-label" for="flexCheckDisabled">
Disabled checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="flexCheckCheckedDisabled" checked disabled>
<label class="form-check-label" for="flexCheckCheckedDisabled">
Disabled checked checkbox
</label>
</div>
单选框
<div class="form-check">
<input class="form-check-input" type="radio" name="flexRadioDefault" id="flexRadioDefault1">
<label class="form-check-label" for="flexRadioDefault1">
Default radio
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="radio" name="flexRadioDefault" id="flexRadioDefault2" checked>
<label class="form-check-label" for="flexRadioDefault2">
Default checked radio
</label>
</div>
单选框禁用
添加disabled
属性后,相关的<label>
会自动调整样式,用更浅的颜色来帮助显示输入的状态。
<div class="form-check">
<input class="form-check-input" type="radio" name="flexRadioDisabled" id="flexRadioDisabled" disabled>
<label class="form-check-label" for="flexRadioDisabled">
Disabled radio
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="radio" name="flexRadioDisabled" id="flexRadioCheckedDisabled" checked disabled>
<label class="form-check-label" for="flexRadioCheckedDisabled">
Disabled checked radio
</label>
</div>
开关
开关具有自定义复选框的标记,但使用 .form-switch
类来呈现切换开关。请考虑使用 role="switch"
以更准确地向支持该角色的辅助技术传达控件的性质。在旧版辅助技术中,它只会作为一个常规复选框作为后备选项公布。开关也支持 disabled
属性。
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="flexSwitchCheckDefault">
<label class="form-check-label" for="flexSwitchCheckDefault">Default switch checkbox input</label>
</div>
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="flexSwitchCheckChecked" checked>
<label class="form-check-label" for="flexSwitchCheckChecked">Checked switch checkbox input</label>
</div>
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="flexSwitchCheckDisabled" disabled>
<label class="form-check-label" for="flexSwitchCheckDisabled">Disabled switch checkbox input</label>
</div>
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="flexSwitchCheckCheckedDisabled" checked disabled>
<label class="form-check-label" for="flexSwitchCheckCheckedDisabled">Disabled checked switch checkbox input</label>
</div>
默认(堆叠)
默认情况下,任何数量的直接同级复选框和单选按钮都将垂直堆叠,并使用 .form-check
适当隔开。
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="defaultCheck1">
<label class="form-check-label" for="defaultCheck1">
Default checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="defaultCheck2" disabled>
<label class="form-check-label" for="defaultCheck2">
Disabled checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="radio" name="exampleRadios" id="exampleRadios1" value="option1" checked>
<label class="form-check-label" for="exampleRadios1">
Default radio
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="radio" name="exampleRadios" id="exampleRadios2" value="option2">
<label class="form-check-label" for="exampleRadios2">
Second default radio
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="radio" name="exampleRadios" id="exampleRadios3" value="option3" disabled>
<label class="form-check-label" for="exampleRadios3">
Disabled radio
</label>
</div>
内联
通过在任何 .form-check
中添加.form-check-inline
,将复选框或单选框组合到同一水平行中。
<div class="form-check form-check-inline">
<input class="form-check-input" type="checkbox" id="inlineCheckbox1" value="option1">
<label class="form-check-label" for="inlineCheckbox1">1</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="checkbox" id="inlineCheckbox2" value="option2">
<label class="form-check-label" for="inlineCheckbox2">2</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="checkbox" id="inlineCheckbox3" value="option3" disabled>
<label class="form-check-label" for="inlineCheckbox3">3 (disabled)</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio1" value="option1">
<label class="form-check-label" for="inlineRadio1">1</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio2" value="option2">
<label class="form-check-label" for="inlineRadio2">2</label>
</div>
<div class="form-check form-check-inline">
<input class="form-check-input" type="radio" name="inlineRadioOptions" id="inlineRadio3" value="option3" disabled>
<label class="form-check-label" for="inlineRadio3">3 (disabled)</label>
</div>
反向
使用.form-check-reverse
修改器类,将复选框、单选框和开关放在反面。
<div class="form-check form-check-reverse">
<input class="form-check-input" type="checkbox" value="" id="reverseCheck1">
<label class="form-check-label" for="reverseCheck1">
Reverse checkbox
</label>
</div>
<div class="form-check form-check-reverse">
<input class="form-check-input" type="checkbox" value="" id="reverseCheck2" disabled>
<label class="form-check-label" for="reverseCheck2">
Disabled reverse checkbox
</label>
</div>
<div class="form-check form-switch form-check-reverse">
<input class="form-check-input" type="checkbox" id="flexSwitchCheckReverse">
<label class="form-check-label" for="flexSwitchCheckReverse">Reverse switch checkbox input</label>
</div>
不带标签
对于没有标签文本的复选框和单选框,请省略.form-check
包装。切记仍要为辅助技术提供某种形式的可访问名称(例如,使用 aria-label
)。详情请参见 表单可访问性概览部分。
<div>
<input class="form-check-input" type="checkbox" id="checkboxNoLabel" value="" aria-label="...">
</div>
<div>
<input class="form-check-input" type="radio" name="radioNoLabel" id="radioNoLabel1" value="" aria-label="...">
</div>
切换按钮
通过在 <label>
元素上使用 .btn
样式而不是 .form-check-label
来创建类似按钮的复选框和单选按钮。如果需要,这些切换按钮还可以进一步组合到按钮组中。
复选框切换按钮
<input type="checkbox" class="btn-check" id="btn-check" autocomplete="off">
<label class="btn btn-primary" for="btn-check">Single toggle</label>
<input type="checkbox" class="btn-check" id="btn-check-2" checked autocomplete="off">
<label class="btn btn-primary" for="btn-check-2">Checked</label>
<input type="checkbox" class="btn-check" id="btn-check-3" autocomplete="off" disabled>
<label class="btn btn-primary" for="btn-check-3">Disabled</label>
<input type="checkbox" class="btn-check" id="btn-check-4" autocomplete="off">
<label class="btn" for="btn-check-4">Single toggle</label>
<input type="checkbox" class="btn-check" id="btn-check-5" checked autocomplete="off">
<label class="btn" for="btn-check-5">Checked</label>
<input type="checkbox" class="btn-check" id="btn-check-6" autocomplete="off" disabled>
<label class="btn" for="btn-check-6">Disabled</label>
单选切换按钮
<input type="radio" class="btn-check" name="options" id="option1" autocomplete="off" checked>
<label class="btn btn-secondary" for="option1">Checked</label>
<input type="radio" class="btn-check" name="options" id="option2" autocomplete="off">
<label class="btn btn-secondary" for="option2">Radio</label>
<input type="radio" class="btn-check" name="options" id="option3" autocomplete="off" disabled>
<label class="btn btn-secondary" for="option3">Disabled</label>
<input type="radio" class="btn-check" name="options" id="option4" autocomplete="off">
<label class="btn btn-secondary" for="option4">Radio</label>
<input type="radio" class="btn-check" name="options-base" id="option5" autocomplete="off" checked>
<label class="btn" for="option5">Checked</label>
<input type="radio" class="btn-check" name="options-base" id="option6" autocomplete="off">
<label class="btn" for="option6">Radio</label>
<input type="radio" class="btn-check" name="options-base" id="option7" autocomplete="off" disabled>
<label class="btn" for="option7">Disabled</label>
<input type="radio" class="btn-check" name="options-base" id="option8" autocomplete="off">
<label class="btn" for="option8">Radio</label>
轮廓样式
支持 .btn
的不同变体,如各种轮廓样式。
<input type="checkbox" class="btn-check" id="btn-check-outlined" autocomplete="off">
<label class="btn btn-outline-primary" for="btn-check-outlined">Single toggle</label><br>
<input type="checkbox" class="btn-check" id="btn-check-2-outlined" checked autocomplete="off">
<label class="btn btn-outline-secondary" for="btn-check-2-outlined">Checked</label><br>
<input type="radio" class="btn-check" name="options-outlined" id="success-outlined" autocomplete="off" checked>
<label class="btn btn-outline-success" for="success-outlined">Checked success radio</label>
<input type="radio" class="btn-check" name="options-outlined" id="danger-outlined" autocomplete="off">
<label class="btn btn-outline-danger" for="danger-outlined">Danger radio</label>
CSS
Sass 变量
Variables for checks:
$form-check-input-width: 1em;
$form-check-min-height: $font-size-base * $line-height-base;
$form-check-padding-start: $form-check-input-width + .5em;
$form-check-margin-bottom: .125rem;
$form-check-label-color: null;
$form-check-label-cursor: null;
$form-check-transition: null;
$form-check-input-active-filter: brightness(90%);
$form-check-input-bg: $input-bg;
$form-check-input-border: var(--#{$prefix}border-width) solid var(--#{$prefix}border-color);
$form-check-input-border-radius: .25em;
$form-check-radio-border-radius: 50%;
$form-check-input-focus-border: $input-focus-border-color;
$form-check-input-focus-box-shadow: $focus-ring-box-shadow;
$form-check-input-checked-color: $component-active-color;
$form-check-input-checked-bg-color: $component-active-bg;
$form-check-input-checked-border-color: $form-check-input-checked-bg-color;
$form-check-input-checked-bg-image: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'><path fill='none' stroke='#{$form-check-input-checked-color}' stroke-linecap='round' stroke-linejoin='round' stroke-width='3' d='m6 10 3 3 6-6'/></svg>");
$form-check-radio-checked-bg-image: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'><circle r='2' fill='#{$form-check-input-checked-color}'/></svg>");
$form-check-input-indeterminate-color: $component-active-color;
$form-check-input-indeterminate-bg-color: $component-active-bg;
$form-check-input-indeterminate-border-color: $form-check-input-indeterminate-bg-color;
$form-check-input-indeterminate-bg-image: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20'><path fill='none' stroke='#{$form-check-input-indeterminate-color}' stroke-linecap='round' stroke-linejoin='round' stroke-width='3' d='M6 10h8'/></svg>");
$form-check-input-disabled-opacity: .5;
$form-check-label-disabled-opacity: $form-check-input-disabled-opacity;
$form-check-btn-check-disabled-opacity: $btn-disabled-opacity;
$form-check-inline-margin-end: 1rem;
Variables for switches:
$form-switch-color: rgba($black, .25);
$form-switch-width: 2em;
$form-switch-padding-start: $form-switch-width + .5em;
$form-switch-bg-image: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'><circle r='3' fill='#{$form-switch-color}'/></svg>");
$form-switch-border-radius: $form-switch-width;
$form-switch-transition: background-position .15s ease-in-out;
$form-switch-focus-color: $input-focus-border-color;
$form-switch-focus-bg-image: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'><circle r='3' fill='#{$form-switch-focus-color}'/></svg>");
$form-switch-checked-color: $component-active-color;
$form-switch-checked-bg-image: url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='-4 -4 8 8'><circle r='3' fill='#{$form-switch-checked-color}'/></svg>");
$form-switch-checked-bg-position: right center;