多选框和单选按钮
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
🌐 Approach
浏览器默认的复选框和单选按钮通过使用 .form-check 得到替换，.form-check 是一系列适用于这两种输入类型的类，它改善了 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。
🌐 Browser default checkboxes and radios are replaced with the help of .form-check, a series of classes for both input types that improves the layout and behavior of their HTML elements, that provide greater customization and cross browser consistency. Checkboxes are for selecting one or several options in a list, while radios are for selecting one option from many.
在结构上，我们的 <input> 和 <label> 是同级元素，而不是 <label> 内的 <input>。这稍微冗长一些，因为你必须指定 id 和 for 属性来关联 <input> 和 <label>。我们对所有的 <input> 状态使用同级选择器（~），比如 :checked 或 :disabled。当与 .form-check-label 类结合时，我们可以根据 <input> 的状态轻松地为每个项目的文本设置样式。
🌐 Structurally, our <input>s and <label>s are sibling elements as opposed to an <input> within a <label>. This is slightly more verbose as you must specify id and for attributes to relate the <input> and <label>. We use the sibling selector (~) for all our <input> states, like :checked or :disabled. When combined with the .form-check-label class, we can easily style the text for each item based on the <input>’s state.
我们的检查使用自定义 Bootstrap 图标来指示已检查或不确定状态。
🌐 Our checks use custom Bootstrap icons to indicate checked or indeterminate states.
选中
🌐 Checks
<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>不定
🌐 Indeterminate
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）。
🌐 Checkboxes can utilize the :indeterminate pseudo class when manually set via JavaScript (there is no available HTML attribute for specifying it).
<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
🌐 Disabled
添加 disabled 属性，相关的 <label> 会自动应用较浅的颜色样式，以帮助指示输入的状态。
🌐 Add the disabled attribute and the associated <label>s are automatically styled to match with a lighter color to help indicate the input’s state.
<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>单选按钮
🌐 Radios
<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
🌐 Disabled
添加 disabled 属性，相关的 <label> 会自动应用较浅的颜色样式，以帮助指示输入的状态。
🌐 Add the disabled attribute and the associated <label>s are automatically styled to match with a lighter color to help indicate the input’s state.
<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
🌐 Switches
开关具有自定义复选框的标记，但使用 .form-switch 类来渲染切换开关。可以考虑使用 role="switch" 来更准确地向支持此角色的辅助技术传达控件的性质。在较旧的辅助技术中，它将作为普通复选框进行通告作为回退。开关还支持 disabled 属性。
🌐 A switch has the markup of a custom checkbox but uses the .form-switch class to render a toggle switch. Consider using role="switch" to more accurately convey the nature of the control to assistive technologies that support this role. In older assistive technologies, it will simply be announced as a regular checkbox as a fallback. Switches also support the disabled attribute.
<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
🌐 Native switches
通过在你的输入中添加 switch 属性，逐步增强移动 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 中使用此属性不会附带任何样式更改，因为我们所有的开关都使用自定义样式。
🌐 Progressively enhance your switches for mobile Safari (iOS 17.4+) by adding a switch attribute to your input to enable haptic feedback when toggling switches, just like native iOS switches. There are no style changes attached to using this attribute in Bootstrap as all our switches use custom styles.
<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>务必在 WebKit 博客 上阅读更多关于开关属性的信息。在 macOS 和 iOS 上的 Safari 17.4 及以上版本中，HTML 中都有原生样式的开关，而其他浏览器则只是回退到标准复选框的外观。在更新版本的 Safari 中，将该属性应用于非 Bootstrap 复选框时，将渲染原生开关样式。
🌐 Be sure to read more about the switch attribute on the WebKit blog. Safari 17.4+ on macOS and iOS both have native-style switches in HTML while other browsers simply fall back to the standard checkbox appearance. Applying the attribute to a non-Bootstrap checkbox in more recent versions of Safari will render a native switch.
默认（堆叠）
🌐 Default (stacked)
默认情况下，任何数量的复选框和单选按钮，如果是直接相邻的兄弟元素，将会垂直排列，并且通过 .form-check 进行适当间距。
🌐 By default, any number of checkboxes and radios that are immediate sibling will be vertically stacked and appropriately spaced with .form-check.
<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
🌐 Inline
通过在任意 .form-check 上添加 .form-check-inline，将同一水平行上的复选框或单选按钮分组。
🌐 Group checkboxes or radios on the same horizontal row by adding .form-check-inline to any .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>撤销
🌐 Reverse
将你的复选框、单选框和开关放在相反的一侧，使用 .form-check-reverse 修饰类。
🌐 Put your checkboxes, radios, and switches on the opposite side with the .form-check-reverse modifier class.
<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>不带标签
🌐 Without labels
对于没有标签文本的复选框和单选按钮，省略封装 .form-check。请记住仍然需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 表单概览可访问性 部分。
🌐 Omit the wrapping .form-check for checkboxes and radios that have no label text. Remember to still provide some form of accessible name for assistive technologies (for instance, using aria-label). See the forms overview accessibility section for details.
<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
🌐 Toggle buttons
通过在 <label> 元素上使用 .btn 样式而不是 .form-check-label，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组合在一个 按钮组 中。
🌐 Create button-like checkboxes and radio buttons by using .btn styles rather than .form-check-label on the <label> elements. These toggle buttons can further be grouped in a button group if needed.
复选框切换按钮
🌐 Checkbox toggle buttons
<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>在视觉上，这些复选框切换按钮与按钮插件切换按钮完全相同。然而，辅助技术对它们的渲染方式不同：复选框切换按钮将被屏幕阅读器宣读为“已选中”/“未选中”（因为尽管外观相同，它们本质上仍然是复选框），而按钮插件切换按钮将被宣读为“按钮”/“按钮已按下”。在这两种方法之间的选择取决于你创建的切换类型，以及当宣读为复选框或实际按钮时，切换是否对用户有意义。
单选切换按钮
🌐 Radio toggle buttons
<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
🌐 Outlined styles
支持 .btn 的不同变体，例如各种轮廓样式。
🌐 Different variants of .btn, such as the various outlined styles, are supported.
<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
🌐 Sass variables
检查变量：
🌐 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;
开关变量：
🌐 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;