Accessibility 类
¥Accessibility class
Accessibility 类提供了检查浏览器的辅助功能树的方法。可访问性树由 屏幕阅读器 或 switches 等辅助技术使用。
¥The Accessibility class provides methods for inspecting the browser's accessibility tree. The accessibility tree is used by assistive technology such as screen readers or switches.
签名：
¥Signature:
export declare class Accessibility
备注
¥Remarks
可访问性是一个非常特定于平台的东西。在不同的平台上，有不同的屏幕阅读器，可能会产生截然不同的输出。
¥Accessibility is a very platform-specific thing. On different platforms, there are different screen readers that might have wildly different output.
Blink - Chrome's rendering engine - 有一个 "可达性树" 的概念，然后将其转换为不同平台特定的 API。Accessibility 命名空间使用户可以访问 Blink Accessibility Tree。
¥Blink - Chrome's rendering engine - has a concept of "accessibility tree", which is then translated into different platform-specific APIs. Accessibility namespace gives users access to the Blink Accessibility Tree.
当从 Blink AX 树转换为特定于平台的 AX 树或通过辅助技术本身时，大多数可访问性树都会被过滤掉。默认情况下，Puppeteer 尝试近似此过滤，仅公开树的 "interesting" 节点。
¥Most of the accessibility tree gets filtered out when converting from Blink AX Tree to Platform-specific AX-Tree or by assistive technologies themselves. By default, Puppeteer tries to approximate this filtering, exposing only the "interesting" nodes of the tree.
此类的构造函数被标记为内部构造函数。第三方代码不应直接调用构造函数或创建扩展 Accessibility 类的子类。
¥The constructor for this class is marked as internal. Third-party code should not call the constructor directly or create subclasses that extend the Accessibility class.
方法
¥Methods
方法 | 修饰符 | 描述 |
|---|---|---|
| snapshot(options) | 捕获可访问性树的当前状态。返回的对象表示页面的根可访问节点。 评论： 注意 Chrome 辅助功能树包含大多数平台和大多数屏幕阅读器都未使用的节点。Puppeteer 也会丢弃它们，以便更容易处理树，除非 |