# 开关 · Switch

- 页面: https://jiguang132.com/zh/resources/astryx/docs/switch
- 资源: Astryx (https://jiguang132.com/zh/resources/astryx.md)
- 全部指南: https://jiguang132.com/zh/resources/astryx/docs.md

开关用于表单输入场景。下面的官方示例展示原生用法与状态，属性名保持上游 API。

## 安装与前置条件

```bash
npm install @astryxdesign/core@0.7.1 @astryxdesign/theme-neutral@0.7.1 @stylexjs/stylex@0.19.0
```

需要 React 19+，按顺序导入基础 CSS 和主题，并设置 Theme Provider。参见[开始使用](/resources/astryx/docs/getting-started)。

## 示例与使用方式

- **开关 · 综合展示 1**：首先体验这个示例，再查看代码理解组件的组合方式。
- **开关 · 禁用状态 2**：可交互查看这一用法的行为，复制代码时保留它实际使用的属性与导入。
- **开关 · 交互示例 3**：可交互查看这一用法的行为，复制代码时保留它实际使用的属性与导入。
- **开关 · 交互示例 4**：可交互查看这一用法的行为，复制代码时保留它实际使用的属性与导入。
- **开关 · 状态 5**：可交互查看这一用法的行为，复制代码时保留它实际使用的属性与导入。

## API 与上游详细参考

优先使用 0.7.1 官方中文说明；上游尚未提供中文的条目保留英文。属性名、类型及默认值保持原生 API，不把示例状态名称当成组件属性。

## Switch

A toggle control for on/off states that take effect immediately. Supports labels, descriptions, loading states, and validation. Use it for settings or preferences that apply instantly. For changes requiring a form submission, use a checkbox instead.

| 属性 | 类型 | 默认值 | 说明 |
|---|---|---|---|
| ref | React.Ref<HTMLInputElement> |  | 转发至底层 <input> 元素的 ref。 |
| label * | string |  | 开关的标签文本（始终渲染以确保无障碍性）。 |
| value * | boolean |  | 开关是开启还是关闭。 |
| onChange | (checked: boolean, e: ChangeEvent<HTMLInputElement>) => void |  | 开关状态变化时触发的回调。 |
| changeAction | (checked: boolean, e: ChangeEvent<HTMLInputElement>) => void \| Promise<void> |  | 在 onChange 之后触发的异步操作。触发乐观 UI 并显示加载旋转器直到 Promise 完成。 |
| isLoading | boolean | false | 开关是否处于加载状态，在滑块内显示旋转器。 |
| isLabelHidden | boolean | false | 视觉上隐藏标签，同时保持屏幕阅读器的无障碍性。 |
| description | string |  | 显示在标签下方的描述文本。 |
| isDisabled | boolean | false | 开关是否被禁用。 |
| size | 'sm' \| 'md' | 'md' | Size variant controlling track and thumb dimensions. sm (32x20px) matches sm checkbox/radio vertical rhythm; md (40x24px, default) matches md checkbox/radio vertical rhythm. |
| htmlName | string |  | 底层复选框输入的 HTML name 属性，用于表单提交（开启时提交 "on"）。 |
| disabledMessage | string |  | Explains why the switch is disabled. With isDisabled, shows a tooltip on hover/keyboard focus and keeps the switch focusable via aria-disabled (toggling stays blocked). Use this instead of wrapping a disabled Switch in Tooltip. Disabled controls swallow the hover events an external Tooltip needs. |
| isOptional | boolean | false | 字段是否为可选。与 isRequired 互斥。 |
| isRequired | boolean | false | 开关是否为必填。与 isOptional 互斥。 |
| status | {type: 'warning' \| 'error' \| 'success', message?: string} |  | 带类型和消息的状态指示器。在开关下方显示彩色消息框，当类型为 "error" 时设置 aria-invalid。 |
| onFocus | (e: FocusEvent<HTMLInputElement>) => void |  | 开关获得焦点时触发的回调。 |
| onBlur | (e: FocusEvent<HTMLInputElement>) => void |  | 开关失去焦点时触发的回调。 |
| labelIcon | IconType |  | 显示在标签文本前面的图标。 |
| labelTooltip | string |  | 在标签末尾的信息图标中显示的工具提示文本。 |
| labelPosition | 'start' \| 'end' | 'end' | 标签出现在开关的哪一侧。"start" 将标签放在开关前面。 |
| labelSpacing | 'hug' \| 'spread' | 'hug' | 标签和开关之间的间距行为。"hug" 将它们并排放置；"spread" 将它们推到容器的两端（全宽）。"default" 是 "hug" 的已弃用别名。 |
| width | SizeValue |  | Width of the field (number = pixels, string used as-is, e.g. "100%"). Sizes the whole field (label, control, and status) so they stay aligned. |

### 使用建议

- Use for settings that apply immediately; the toggle should take effect without a separate save action.
- Pair with a clear, concise label that describes the setting being controlled.
- 避免：Use for options that require a form submission to take effect; use a checkbox instead.
- 避免：Use a switch for multi-state values; it's strictly on/off.
- 避免：Wrap a disabled switch in Tooltip to explain why it is disabled; disabled controls swallow the hover events the wrapper needs. Use the disabledMessage prop instead.

### 主题 API

```json
{
  "targets": [
    {
      "className": "astryx-switch",
      "visualProps": [
        "size"
      ],
      "states": [
        "checked",
        "disabled"
      ]
    },
    {
      "className": "astryx-switch-thumb",
      "visualProps": [
        "size"
      ],
      "states": [
        "checked"
      ]
    },
    {
      "className": "astryx-switch-field",
      "visualProps": [
        "labelPosition",
        "labelSpacing"
      ]
    },
    {
      "className": "astryx-switch-label"
    }
  ]
}
```

### 无障碍

- **Track and thumb**: The on and off tracks must each have at least 3:1 contrast with the surface behind them, and the thumb with its track. For Hover and Pointer down, measure the final colors after the tint and the pressed overlay are applied. — 3:1

### 组件结构

- **Field**: Container arranging the switch, label, and feedback.
- **Track**: Pill-shaped surface that shows the off or on state.
- **Thumb**: Indicator that moves across the track when state changes.
- **Label**: Text identifying the setting controlled by the switch.
- **Description**: Helper text below the label.
- **Spinner**: Loading indicator shown inside the thumb while busy.
- **Status message**: Error, warning, or success message below the switch.

---

JGuang 全部资源索引: https://jiguang132.com/llms.txt