手風琴（Accordion）

結合我們的摺疊 JavaScript 外掛來建構垂直摺疊的手風琴元件。

本頁內容

運作原理（How it works）

手風琴內部使用摺疊來實現可摺疊功能。

此元件的動畫效果取決於 prefers-reduced-motion 媒體查詢。請參閱我們無障礙文件中的減少動態效果章節。

範例（Example）

點擊下方的手風琴來展開/摺疊手風琴內容。

要渲染預設展開的手風琴：

在 .accordion-collapse 元素上加入 .show 類別。
從 .accordion-button 元素移除 .collapsed 類別，並將其 aria-expanded 屬性設為 true。

This is the first item's accordion body. It is shown by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the .accordion-body, though the transition does limit overflow.

This is the second item's accordion body. It is hidden by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the .accordion-body, though the transition does limit overflow.

This is the third item's accordion body. It is hidden by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the .accordion-body, though the transition does limit overflow.

html

<div class="accordion" id="accordionExample">
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button" type="button" data-bs-toggle="collapse" data-bs-target="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
        Accordion Item #1
      </button>
    </h2>
    <div id="collapseOne" class="accordion-collapse collapse show" data-bs-parent="#accordionExample">
      <div class="accordion-body">
        <strong>This is the first item's accordion body.</strong> It is shown by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the <code>.accordion-body</code>, though the transition does limit overflow.
      </div>
    </div>
  </div>
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseTwo" aria-expanded="false" aria-controls="collapseTwo">
        Accordion Item #2
      </button>
    </h2>
    <div id="collapseTwo" class="accordion-collapse collapse" data-bs-parent="#accordionExample">
      <div class="accordion-body">
        <strong>This is the second item's accordion body.</strong> It is hidden by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the <code>.accordion-body</code>, though the transition does limit overflow.
      </div>
    </div>
  </div>
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseThree" aria-expanded="false" aria-controls="collapseThree">
        Accordion Item #3
      </button>
    </h2>
    <div id="collapseThree" class="accordion-collapse collapse" data-bs-parent="#accordionExample">
      <div class="accordion-body">
        <strong>This is the third item's accordion body.</strong> It is hidden by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the <code>.accordion-body</code>, though the transition does limit overflow.
      </div>
    </div>
  </div>
</div>

無邊距樣式（Flush）

加入 .accordion-flush 來移除一些邊框和圓角，使手風琴與其父容器邊緣對齊。

Placeholder content for this accordion, which is intended to demonstrate the .accordion-flush class. This is the first item's accordion body.

Placeholder content for this accordion, which is intended to demonstrate the .accordion-flush class. This is the second item's accordion body. Let's imagine this being filled with some actual content.

Placeholder content for this accordion, which is intended to demonstrate the .accordion-flush class. This is the third item's accordion body. Nothing more exciting happening here in terms of content, but just filling up the space to make it look, at least at first glance, a bit more representative of how this would look in a real-world application.

html

<div class="accordion accordion-flush" id="accordionFlushExample">
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#flush-collapseOne" aria-expanded="false" aria-controls="flush-collapseOne">
        Accordion Item #1
      </button>
    </h2>
    <div id="flush-collapseOne" class="accordion-collapse collapse" data-bs-parent="#accordionFlushExample">
      <div class="accordion-body">Placeholder content for this accordion, which is intended to demonstrate the <code>.accordion-flush</code> class. This is the first item's accordion body.</div>
    </div>
  </div>
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#flush-collapseTwo" aria-expanded="false" aria-controls="flush-collapseTwo">
        Accordion Item #2
      </button>
    </h2>
    <div id="flush-collapseTwo" class="accordion-collapse collapse" data-bs-parent="#accordionFlushExample">
      <div class="accordion-body">Placeholder content for this accordion, which is intended to demonstrate the <code>.accordion-flush</code> class. This is the second item's accordion body. Let's imagine this being filled with some actual content.</div>
    </div>
  </div>
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#flush-collapseThree" aria-expanded="false" aria-controls="flush-collapseThree">
        Accordion Item #3
      </button>
    </h2>
    <div id="flush-collapseThree" class="accordion-collapse collapse" data-bs-parent="#accordionFlushExample">
      <div class="accordion-body">Placeholder content for this accordion, which is intended to demonstrate the <code>.accordion-flush</code> class. This is the third item's accordion body. Nothing more exciting happening here in terms of content, but just filling up the space to make it look, at least at first glance, a bit more representative of how this would look in a real-world application.</div>
    </div>
  </div>
</div>

保持開啟（Always open）

在每個 .accordion-collapse 上省略 data-bs-parent 屬性，使手風琴項目在另一個項目開啟時保持開啟狀態。

html

<div class="accordion" id="accordionPanelsStayOpenExample">
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button" type="button" data-bs-toggle="collapse" data-bs-target="#panelsStayOpen-collapseOne" aria-expanded="true" aria-controls="panelsStayOpen-collapseOne">
        Accordion Item #1
      </button>
    </h2>
    <div id="panelsStayOpen-collapseOne" class="accordion-collapse collapse show">
      <div class="accordion-body">
        <strong>This is the first item's accordion body.</strong> It is shown by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the <code>.accordion-body</code>, though the transition does limit overflow.
      </div>
    </div>
  </div>
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#panelsStayOpen-collapseTwo" aria-expanded="false" aria-controls="panelsStayOpen-collapseTwo">
        Accordion Item #2
      </button>
    </h2>
    <div id="panelsStayOpen-collapseTwo" class="accordion-collapse collapse">
      <div class="accordion-body">
        <strong>This is the second item's accordion body.</strong> It is hidden by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the <code>.accordion-body</code>, though the transition does limit overflow.
      </div>
    </div>
  </div>
  <div class="accordion-item">
    <h2 class="accordion-header">
      <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#panelsStayOpen-collapseThree" aria-expanded="false" aria-controls="panelsStayOpen-collapseThree">
        Accordion Item #3
      </button>
    </h2>
    <div id="panelsStayOpen-collapseThree" class="accordion-collapse collapse">
      <div class="accordion-body">
        <strong>This is the third item's accordion body.</strong> It is hidden by default, until the collapse plugin adds the appropriate classes that we use to style each element. These classes control the overall appearance, as well as the showing and hiding via CSS transitions. You can modify any of this with custom CSS or overriding our default variables. It's also worth noting that just about any HTML can go within the <code>.accordion-body</code>, though the transition does limit overflow.
      </div>
    </div>
  </div>
</div>

無障礙（Accessibility）

請閱讀摺疊無障礙章節以取得更多資訊。

CSS

變數（Variables）

Added in v5.2.0

作為 Bootstrap 持續演進的 CSS 變數方法的一部分，手風琴現在在 .accordion 上使用本地 CSS 變數來增強即時自訂功能。CSS 變數的值透過 Sass 設定，因此 Sass 自訂仍然受支援。

scss/_accordion.scss

--#{$prefix}accordion-color: #{$accordion-color};
--#{$prefix}accordion-bg: #{$accordion-bg};
--#{$prefix}accordion-transition: #{$accordion-transition};
--#{$prefix}accordion-border-color: #{$accordion-border-color};
--#{$prefix}accordion-border-width: #{$accordion-border-width};
--#{$prefix}accordion-border-radius: #{$accordion-border-radius};
--#{$prefix}accordion-inner-border-radius: #{$accordion-inner-border-radius};
--#{$prefix}accordion-btn-padding-x: #{$accordion-button-padding-x};
--#{$prefix}accordion-btn-padding-y: #{$accordion-button-padding-y};
--#{$prefix}accordion-btn-color: #{$accordion-button-color};
--#{$prefix}accordion-btn-bg: #{$accordion-button-bg};
--#{$prefix}accordion-btn-icon: #{escape-svg($accordion-button-icon)};
--#{$prefix}accordion-btn-icon-width: #{$accordion-icon-width};
--#{$prefix}accordion-btn-icon-transform: #{$accordion-icon-transform};
--#{$prefix}accordion-btn-icon-transition: #{$accordion-icon-transition};
--#{$prefix}accordion-btn-active-icon: #{escape-svg($accordion-button-active-icon)};
--#{$prefix}accordion-btn-focus-box-shadow: #{$accordion-button-focus-box-shadow};
--#{$prefix}accordion-body-padding-x: #{$accordion-body-padding-x};
--#{$prefix}accordion-body-padding-y: #{$accordion-body-padding-y};
--#{$prefix}accordion-active-color: #{$accordion-button-active-color};
--#{$prefix}accordion-active-bg: #{$accordion-button-active-bg};

Sass 變數（Sass variables）

scss/_variables.scss

$accordion-padding-y:                     1rem;
$accordion-padding-x:                     1.25rem;
$accordion-color:                         var(--#{$prefix}body-color);
$accordion-bg:                            var(--#{$prefix}body-bg);
$accordion-border-width:                  var(--#{$prefix}border-width);
$accordion-border-color:                  var(--#{$prefix}border-color);
$accordion-border-radius:                 var(--#{$prefix}border-radius);
$accordion-inner-border-radius:           subtract($accordion-border-radius, $accordion-border-width);

$accordion-body-padding-y:                $accordion-padding-y;
$accordion-body-padding-x:                $accordion-padding-x;

$accordion-button-padding-y:              $accordion-padding-y;
$accordion-button-padding-x:              $accordion-padding-x;
$accordion-button-color:                  var(--#{$prefix}body-color);
$accordion-button-bg:                     var(--#{$prefix}accordion-bg);
$accordion-transition:                    $btn-transition, border-radius .15s ease;
$accordion-button-active-bg:              var(--#{$prefix}primary-bg-subtle);
$accordion-button-active-color:           var(--#{$prefix}primary-text-emphasis);

// fusv-disable
$accordion-button-focus-border-color:     $input-focus-border-color; // Deprecated in v5.3.3
// fusv-enable
$accordion-button-focus-box-shadow:       $btn-focus-box-shadow;

$accordion-icon-width:                    1.25rem;
$accordion-icon-color:                    $body-color;
$accordion-icon-active-color:             $primary-text-emphasis;
$accordion-icon-transition:               transform .2s ease-in-out;
$accordion-icon-transform:                rotate(-180deg);

$accordion-button-icon:         url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='#{$accordion-icon-color}' stroke-linecap='round' stroke-linejoin='round'><path d='m2 5 6 6 6-6'/></svg>");
$accordion-button-active-icon:  url("data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='none' stroke='#{$accordion-icon-active-color}' stroke-linecap='round' stroke-linejoin='round'><path d='m2 5 6 6 6-6'/></svg>");

使用方式（Usage）

摺疊外掛使用一些類別來處理繁重的工作：

.collapse 隱藏內容
.collapse.show 顯示內容
.collapsing 在轉場開始時加入，並在轉場結束時移除

這些類別可以在 _transitions.scss 中找到。

透過 data 屬性（Via data attributes）

只需在元素上加入 data-bs-toggle="collapse" 和 data-bs-target，即可自動指定一個或多個可摺疊元素的控制。data-bs-target 屬性接受 CSS 選擇器來套用摺疊功能。請確保在可摺疊元素上加入 collapse 類別。如果您希望它預設為開啟狀態，請加入額外的 show 類別。

要在可摺疊區域加入手風琴群組管理，請加入 data 屬性 data-bs-parent="#selector"。

透過 JavaScript（Via JavaScript）

手動啟用：

const accordionCollapseElementList = document.querySelectorAll('#myAccordion .collapse')
const accordionCollapseList = [...accordionCollapseElementList].map(accordionCollapseEl => new bootstrap.Collapse(accordionCollapseEl))

選項（Options）

由於選項可以透過 data 屬性或 JavaScript 傳遞，您可以將選項名稱附加到 data-bs-，例如 data-bs-animation="{value}"。透過 data 屬性傳遞選項時，請確保將選項名稱的大小寫類型從「camelCase」更改為「kebab-case」。例如，使用 data-bs-custom-class="beautifier" 而不是 data-bs-customClass="beautifier"。

從 Bootstrap 5.2.0 開始，所有元件都支援實驗性的保留 data 屬性 data-bs-config，可以將簡單的元件配置作為 JSON 字串存放。當元素同時具有 data-bs-config='{"delay":0, "title":123}' 和 data-bs-title="456" 屬性時，最終的 title 值將是 456，個別的 data 屬性將覆寫 data-bs-config 中給定的值。此外，現有的 data 屬性也能夠存放 JSON 值，例如 data-bs-delay='{"show":0,"hide":150}'。

最終的配置物件是 data-bs-config、data-bs- 和 js object 的合併結果，其中最後給定的鍵值對會覆寫其他的。

名稱	型別	預設值	說明
`parent`	選擇器、DOM 元素	`null`	如果提供了 parent，則當此可摺疊項目顯示時，指定父元素下的所有可摺疊元素都將被關閉（類似於傳統手風琴行為——這取決於 `card` 類別）。該屬性必須設定在目標可摺疊區域上。
`toggle`	布林值	`true`	在呼叫時切換可摺疊元素。

方法（Methods）

所有 API 方法都是非同步的，並會啟動一個過渡效果。 它們會在過渡開始後立即回傳給呼叫者，但在過渡結束之前。此外，對正在過渡中的元件進行方法呼叫將被忽略。在我們的 JavaScript 文件中了解更多。

將您的內容啟用為可摺疊元素。接受一個可選的選項 object。

您可以使用建構函式建立摺疊實例，例如：

const bsCollapse = new bootstrap.Collapse('#myCollapse', {
  toggle: false
})

方法	說明
`dispose`	銷毀元素的摺疊功能。（移除儲存在 DOM 元素上的資料）
`getInstance`	靜態方法，允許您取得與 DOM 元素關聯的摺疊實例，您可以這樣使用：`bootstrap.Collapse.getInstance(element)`。
`getOrCreateInstance`	靜態方法，返回與 DOM 元素關聯的摺疊實例，如果尚未初始化則建立一個新的。您可以這樣使用：`bootstrap.Collapse.getOrCreateInstance(element)`。
`hide`	隱藏可摺疊元素。在可摺疊元素實際被隱藏之前返回給呼叫者（例如，在 `hidden.bs.collapse` 事件發生之前）。
`show`	顯示可摺疊元素。在可摺疊元素實際被顯示之前返回給呼叫者（例如，在 `shown.bs.collapse` 事件發生之前）。
`toggle`	將可摺疊元素切換為顯示或隱藏。在可摺疊元素實際被顯示或隱藏之前返回給呼叫者（即在 `shown.bs.collapse` 或 `hidden.bs.collapse` 事件發生之前）。

事件（Events）

Bootstrap 的摺疊類別公開了一些事件，用於掛鉤摺疊功能。

事件類型	說明
`hide.bs.collapse`	當呼叫 `hide` 方法時立即觸發此事件。
`hidden.bs.collapse`	當摺疊元素對使用者隱藏完成時觸發此事件（將等待 CSS 轉場完成）。
`show.bs.collapse`	當呼叫 `show` 實例方法時立即觸發此事件。
`shown.bs.collapse`	當摺疊元素對使用者顯示完成時觸發此事件（將等待 CSS 轉場完成）。

const myCollapsible = document.getElementById('myCollapsible')
myCollapsible.addEventListener('hidden.bs.collapse', event => {
  // do something...
})