复选框与单选框
使用我们完全重写的复选框与单选按钮,创建跨浏览器和跨设备一致的复选框和单选按钮。
方法
浏览器默认的复选框和单选框在...的帮助下被替换 .form-check一系列针对两种输入类型的类,用于改进其 HTML 元素的布局和行为,提供更大的自定义性和跨浏览器一致性。复选框用于在列表中选择一个或多个选项,而单选按钮用于从多个选项中选择一个。
在结构上,我们的 <input>和 <label>s 是兄弟元素,而不是一个 <input> 在……之内 <label>. 这稍微更啰嗦,因为你必须指定 id 和 for 与……相关的属性 <input> 和 <label>. 我们使用兄弟选择器(~) 对我们所有的 <input> 州,比如 :checked 或 :disabled. 当与...结合时 .form-check-label 类,我们可以轻松地根据每个项目来设置文本样式 <input>的状态。
我们的复选框使用自定义的 Bootstrap 图标来表示选中或不确定状态。
检查
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="checkDefault">
<label class="form-check-label" for="checkDefault">
Default checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="checkChecked" checked>
<label class="form-check-label" for="checkChecked">
Checked checkbox
</label>
</div>不确定
复选框在通过 JavaScript 手动设置时可以使用 :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="checkIndeterminate">
<label class="form-check-label" for="checkIndeterminate">
Indeterminate checkbox
</label>
</div>禁用
添加 disabled 属性后,相关的 <label> 会自动应用更浅的颜色样式,以帮助指示输入的状态。
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="checkIndeterminateDisabled" disabled>
<label class="form-check-label" for="checkIndeterminateDisabled">
Disabled indeterminate checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="checkDisabled" disabled>
<label class="form-check-label" for="checkDisabled">
Disabled checkbox
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="checkbox" value="" id="checkCheckedDisabled" checked disabled>
<label class="form-check-label" for="checkCheckedDisabled">
Disabled checked checkbox
</label>
</div>单选框
<div class="form-check">
<input class="form-check-input" type="radio" name="radioDefault" id="radioDefault1">
<label class="form-check-label" for="radioDefault1">
Default radio
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="radio" name="radioDefault" id="radioDefault2" checked>
<label class="form-check-label" for="radioDefault2">
Default checked radio
</label>
</div>禁用
添加 disabled 属性后,相关的 <label> 会自动应用更浅的颜色样式,以帮助指示输入的状态。
<div class="form-check">
<input class="form-check-input" type="radio" name="radioDisabled" id="radioDisabled" disabled>
<label class="form-check-label" for="radioDisabled">
Disabled radio
</label>
</div>
<div class="form-check">
<input class="form-check-input" type="radio" name="radioDisabled" id="radioCheckedDisabled" checked disabled>
<label class="form-check-label" for="radioCheckedDisabled">
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。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。在较旧的辅助技术中,它将作为常规复选框进行简单宣布作为回退。开关还支持 disabled 属性。
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="switchCheckDefault">
<label class="form-check-label" for="switchCheckDefault">Default switch checkbox input</label>
</div>
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="switchCheckChecked" checked>
<label class="form-check-label" for="switchCheckChecked">Checked switch checkbox input</label>
</div>
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="switchCheckDisabled" disabled>
<label class="form-check-label" for="switchCheckDisabled">Disabled switch checkbox input</label>
</div>
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" role="switch" id="switchCheckCheckedDisabled" checked disabled>
<label class="form-check-label" for="switchCheckCheckedDisabled">Disabled checked switch checkbox input</label>
</div>原生开关
通过在输入中添加switch属性,逐步增强你在移动 Safari(iOS 17.4)上的开关,以在切换开关时启用触觉反馈,就像原生 iOS 开关一样。在 Bootstrap 中使用此属性不会带来样式更改,因为我们所有的开关都使用自定义样式。
<div class="form-check form-switch">
<input class="form-check-input" type="checkbox" value="" id="checkNativeSwitch" switch>
<label class="form-check-label" for="checkNativeSwitch">
Native switch haptics
</label>
</div>一定要在 WebKit 博客上阅读更多关于开关属性的信息。macOS 和 iOS 上的 Safari 17.4 都在 HTML 中提供原生风格的开关,而其他浏览器则仅回退到标准复选框外观。在更新版本的 Safari 中,将此属性应用于非 Bootstrap 复选框将呈现原生开关。
默认(堆叠)
默认情况下,任何数量的复选框和单选框,如果是直接兄弟元素,将会垂直堆叠并使用 .form-check 适当间隔。
<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
通过添加在同一水平行上的组复选框或单选按钮 .form-check-inline 到任何 .form-check.
<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>反转
使用 .form-check-reverse 修饰类将你的复选框、单选按钮和开关放在相反的一侧。
<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="switchCheckReverse">
<label class="form-check-label" for="switchCheckReverse">Reverse switch checkbox input</label>
</div>
无标签
对于没有标签文本的复选框和单选按钮,请省略包裹的 .form-check。请记住仍然需要为辅助技术提供某种可访问名称(例如,使用 aria-label)。详细信息请参见 表单概述可访问性 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
通过使用 .btn 样式而不是 .form-check-label 样式在 <label> 元素上创建类似按钮的复选框和单选按钮。如果需要,这些切换按钮可以进一步分组在 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>
从视觉上看,这些复选框切换按钮与按钮插件切换按钮完全相同。然而,它们在辅助技术中的表现方式不同:屏幕阅读器将以“已选中/未选中”来朗读复选框切换按钮(因为尽管外观如此,它们本质上仍然是复选框),而按钮插件切换按钮将被朗读为“按钮/按钮已按下”。在这两种方法之间的选择取决于你所创建的切换类型,以及当切换被朗读为复选框或实际按钮时是否对用户有意义。
单选按钮切换
<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,例如各种轮廓样式。
<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
检查变量:
$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;
开关的变量:
$form-switch-color: rgba($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;