你如何实现UIAccessibility协议？

Question

的 “辅助功能编程指南对于iOS” 规定：

Another way is to implement the isAccessibilityElement method of the UIAccessibility protocol in the implementation of your custom subclass. The following code snippet shows how to do this:

但是当我这样做，如下面的代码：

class UITextLayerLabel : UIView, UIAccessibility { 

的XCode返回我这个错误：

[...] Use of undeclared type 'UIAccessibility' 

我错过了什么？具体的进口？该协议仍可用于iOS 10/XCode8吗？

Answer 1

如指出here，UIAccessibility是一个非正式协议。有关非正式协议与正式协议之间的区别，请参见here。基本上没有类型叫UIAccessibility。实际上，UIView已经符合UIAccessibility。要使您的自定义视图可访问，只需覆盖以accessibility开头的属性和方法。

所以，当你需要实现UIAccessibility？如前所述here，

You can use UIAccessibilityElement to provide information about an icon or text image is not automatically accessible because it does not inherit from UIView (or UIControl). A view that contains such nonview items creates an instance of UIAccessibilityElement to represent each item that needs to be accessible.