158 lines
3.6 KiB
Markdown
158 lines
3.6 KiB
Markdown
---
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id: accessibilityinfo
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title: AccessibilityInfo
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layout: docs
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category: APIs
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permalink: docs/accessibilityinfo.html
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next: actionsheetios
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previous: webview
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---
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Sometimes it's useful to know whether or not the device has a screen reader that is currently active. The `AccessibilityInfo` API is designed for this purpose. You can use it to query the current state of the screen reader as well as to register to be notified when the state of the screen reader changes.
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Here's a small example illustrating how to use `AccessibilityInfo`:
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```javascript
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class ScreenReaderStatusExample extends React.Component {
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state = {
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screenReaderEnabled: false,
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}
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componentDidMount() {
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AccessibilityInfo.addEventListener(
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'change',
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this._handleScreenReaderToggled
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);
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AccessibilityInfo.fetch().done((isEnabled) => {
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this.setState({
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screenReaderEnabled: isEnabled
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});
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});
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}
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componentWillUnmount() {
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AccessibilityInfo.removeEventListener(
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'change',
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this._handleScreenReaderToggled
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);
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}
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_handleScreenReaderToggled = (isEnabled) => {
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this.setState({
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screenReaderEnabled: isEnabled,
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});
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}
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render() {
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return (
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<View>
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<Text>
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The screen reader is {this.state.screenReaderEnabled ? 'enabled' : 'disabled'}.
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</Text>
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</View>
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);
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}
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}
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```
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### Methods
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- [`fetch`](docs/accessibilityinfo.html#fetch)
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- [`addEventListener`](docs/accessibilityinfo.html#addeventlistener)
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- [`setAccessibilityFocus`](docs/accessibilityinfo.html#setaccessibilityfocus)
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- [`announceForAccessibility`](docs/accessibilityinfo.html#announceforaccessibility)
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- [`removeEventListener`](docs/accessibilityinfo.html#removeeventlistener)
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---
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# Reference
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## Methods
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### `fetch()`
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```javascript
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AccessibilityInfo.fetch()
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```
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Query whether a screen reader is currently enabled. Returns a promise which resolves to a boolean. The result is `true` when a screen reader is enabled and `false` otherwise.
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---
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### `addEventListener()`
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```javascript
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AccessibilityInfo.addEventListener(eventName, handler)
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```
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Add an event handler.
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| Name | Type | Required | Description |
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| - | - | - | - |
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| eventName | string | Yes | Name of the event |
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| handler | function | Yes | Event handler |
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Supported events:
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- `change`: Fires when the state of the screen reader changes. The argument
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to the event handler is a boolean. The boolean is `true` when a screen
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reader is enabled and `false` otherwise.
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- `announcementFinished`: iOS-only event. Fires when the screen reader has
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finished making an announcement. The argument to the event handler is a dictionary
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with these keys:
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- `announcement`: The string announced by the screen reader.
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- `success`: A boolean indicating whether the announcement was successfully made.
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---
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### `setAccessibilityFocus()`
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```javascript
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AccessibilityInfo.setAccessibilityFocus(reactTag)
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```
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Set accessibility focus to a React component.
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| Name | Type | Required | Description |
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| - | - | - | - |
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| reactTag | number | Yes | React component tag |
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| Platform |
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| - |
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| iOS |
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---
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### `announceForAccessibility()`
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```javascript
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AccessibilityInfo.announceForAccessibility(announcement)
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```
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Post a string to be announced by the screen reader.
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| Name | Type | Required | Description |
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| - | - | - | - |
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| announcement | string | Yes | String to be announced |
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| Platform |
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| - |
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| iOS |
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---
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### `removeEventListener()`
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```javascript
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AccessibilityInfo.removeEventListener(eventName, handler)
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```
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Remove an event handler.
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| Name | Type | Required | Description |
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| - | - | - | - |
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| eventName | string | Yes | Name of the event |
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| handler | function | Yes | Event handler |
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