ios - 你如何实现 UIAccessibility 协议(protocol)？

Question

“iOS 辅助功能编程指南”指出:

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:

但是当我这样做的时候，如下代码所示:

class UITextLayerLabel : UIView, UIAccessibility {

XCode 返回这个错误:

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

我错过了什么？一个特定的进口？该协议(protocol)是否仍适用于 iOS 10/XCode8？

Answer 1

正如指出的那样here , UIAccessibility 是一个非正式的协议(protocol)。有关非正式协议(protocol)和正式协议(protocol)之间的区别，请参阅 here .

基本上，没有名为UIAccessibility 的类型。实际上，UIView 已经符合 UIAccessibility。要使您的自定义 View 可访问，只需覆盖以 accessibility 开头的属性和方法。

那么什么时候需要实现UIAccessibility呢？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.