AccessibilityInfo

有时候我们希望知道用户的设备是否正在运行读屏应用。AccessibilityInfo正是用于此目的。你可以用它来查询读屏应用的当前状态，并且可以监听其状态变化。

示例

函数式组件

Class 组件

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文档

方法

isBoldTextEnabled()

static isBoldTextEnabled()

iOS-Only. Query whether a bold text is currently enabled. Returns a promise which resolves to a boolean. The result is true when bold text is enabled and false otherwise.

isGrayscaleEnabled()

static isGrayscaleEnabled()

iOS-Only. Query whether grayscale is currently enabled. Returns a promise which resolves to a boolean. The result is true when grayscale is enabled and false otherwise.

isInvertColorsEnabled()

static isInvertColorsEnabled()

iOS-Only. Query whether invert colors is currently enabled. Returns a promise which resolves to a boolean. The result is true when invert colors is enabled and false otherwise.

isReduceMotionEnabled()

static isReduceMotionEnabled()

Query whether reduce motion is currently enabled. Returns a promise which resolves to a boolean. The result is true when reduce motion is enabled and false otherwise.

isReduceTransparencyEnabled()

static isReduceTransparencyEnabled()

iOS-Only. Query whether reduce transparency is currently enabled. Returns a promise which resolves to a boolean. The result is true when a reduce transparency is enabled and false otherwise.

isScreenReaderEnabled()

static isScreenReaderEnabled()

查询读屏应用当前是否开启。返回值为一个 promise，最终解析值为一个布尔值。true表示开启状态，false反之。

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addEventListener()

static addEventListener(eventName, handler)

添加一个监听函数，支持的事件类型如下：

• boldTextChanged: iOS-only event. Fires when the state of the bold text toggle changes. The argument to the event handler is a boolean. The boolean is true when bold text is enabled and false otherwise.
• grayscaleChanged: iOS-only event. Fires when the state of the gray scale toggle changes. The argument to the event handler is a boolean. The boolean is true when a gray scale is enabled and false otherwise.
• invertColorsChanged: iOS-only event. Fires when the state of the invert colors toggle changes. The argument to the event handler is a boolean. The boolean is true when invert colors is enabled and false otherwise.
• reduceMotionChanged: Fires when the state of the reduce motion toggle changes. The argument to the event handler is a boolean. The boolean is true when a reduce motion is enabled (or when "Transition Animation Scale" in "Developer options" is "Animation off") and false otherwise.
• screenReaderChanged: 读屏应用状态改变时触发。传递给监听函数的参数为布尔值，true表示开启状态，false反之。
• reduceTransparencyChanged: iOS-only event. Fires when the state of the reduce transparency toggle changes. The argument to the event handler is a boolean. The boolean is true when reduce transparency is enabled and false otherwise.
• announcementFinished: 仅 iOS 可用。在读屏软件完成一次朗读后触发。传递给监听函数的参数为一个字典，包含以下两个字段：
  • announcement: 读屏软件所读的字符串。
  • success: 此次朗读是否成功完成。

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setAccessibilityFocus()

static setAccessibilityFocus(reactTag)

将读屏软件的焦点设置到某个 react 组件上。在 Android 等同于调用 UIManager.sendAccessibilityEvent(reactTag, UIManager.AccessibilityEventTypes.typeViewFocused);.

Note: Make sure that any View you want to receive the accessibility focus has accessible={true}.

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announceForAccessibility()

static announceForAccessibility(announcement)

发送一个字符串给读屏应用朗读。

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removeEventListener()

static removeEventListener(eventName, handler)

移除一个监听函数。