Select

~~Customize the native <select>s with custom CSS that changes the element’s initial appearance.~~定制原生<select>，使用自定义CSS更改元素的初始外观。

~~On this page~~本页内容

Default默认

~~Custom <select> menus need only a custom class, .form-select to trigger the custom styles.~~ 定制<select>菜单只需要自定义类.form-select即可触发自定义样式。~~Custom styles are limited to the <select>’s initial appearance and cannot modify the <option>s due to browser limitations.~~自定义样式仅限于 <select>的初始外观，无法修改<option>，这是由于浏览器的限制。

<select class="form-select" aria-label="Default select example">
<option selected>Open this select menu</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>

Sizing尺寸

~~You may also choose from small and large custom selects to match our similarly sized text inputs.~~您也可以从大小定制选择中进行选择，以匹配我们类似大小的文本输入。

<select class="form-select form-select-lg mb-3" aria-label=".form-select-lg example">
<option selected>Open this select menu</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
<select class="form-select form-select-sm" aria-label=".form-select-sm example">
<option selected>Open this select menu</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>

~~The multiple attribute is also supported:~~还支持multiple属性：

<select class="form-select" multiple aria-label="multiple select example">
<option selected>Open this select menu</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>

~~As is the size attribute:~~与size属性相同：

<select class="form-select" size="3" aria-label="size 3 select example">
<option selected>Open this select menu</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>

Disabled禁用

~~Add the disabled boolean attribute on a select to give it a grayed out appearance and remove pointer events.~~在select上添加disabled的布尔属性，使其显示为灰色，并删除指针事件。

<select class="form-select" aria-label="Disabled select example" disabled>
<option selected>Open this select menu</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>

Sass

Variables变量

$form-select-padding-y:             $input-padding-y;
$form-select-padding-x:             $input-padding-x;
$form-select-font-family:           $input-font-family;
$form-select-font-size:             $input-font-size;
$form-select-indicator-padding:     $form-select-padding-x * 3; // Extra padding for background-image
$form-select-font-weight:           $input-font-weight;
$form-select-line-height:           $input-line-height;
$form-select-color:                 $input-color;
$form-select-bg:                    $input-bg;
$form-select-disabled-color:        null;
$form-select-disabled-bg:           $gray-200;
$form-select-disabled-border-color: $input-disabled-border-color;
$form-select-bg-position:           right $form-select-padding-x center;
$form-select-bg-size:               16px 12px; // In pixels because image dimensions
$form-select-indicator-color:       $gray-800;
$form-select-indicator:             url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'><path fill='none' stroke='#{$form-select-indicator-color}' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M2 5l6 6 6-6'/></svg>");
$form-select-feedback-icon-padding-end: $form-select-padding-x * 2.5 + $form-select-indicator-padding;
$form-select-feedback-icon-position:    center right $form-select-indicator-padding;
$form-select-feedback-icon-size:        $input-height-inner-half $input-height-inner-half;
$form-select-border-width:        $input-border-width;
$form-select-border-color:        $input-border-color;
$form-select-border-radius:       $border-radius;
$form-select-box-shadow:          $box-shadow-inset;
$form-select-focus-border-color:  $input-focus-border-color;
$form-select-focus-width:         $input-focus-width;
$form-select-focus-box-shadow:    0 0 0 $form-select-focus-width $input-btn-focus-color;
$form-select-padding-y-sm:        $input-padding-y-sm;
$form-select-padding-x-sm:        $input-padding-x-sm;
$form-select-font-size-sm:        $input-font-size-sm;
$form-select-padding-y-lg:        $input-padding-y-lg;
$form-select-padding-x-lg:        $input-padding-x-lg;
$form-select-font-size-lg:        $input-font-size-lg;
$form-select-transition:          $input-transition;