This blog was inspired by Jeff Watkins’ series of blogs on UIButton. UIButton is a fundamental part of building interfaces on iOS. So much so, that it probably doesn’t get the love it deserves. But it’s also really powerful and customisable when used correctly.

该博客的灵感来自Jeff Watkins在UIButton上的 一系列 博客 。 UIButton是在iOS上构建界面的基本部分。 如此之多，以至于它可能无法得到应有的爱。 但是，如果使用正确，它也确实非常强大且可自定义。

Accessibility labels on iOS I feel are very similar. They’re fundamental to how accessibility works on iOS, yet I think they suffer from a few PR issues. Firstly, Apple has done such a good job with them that we often don’t give the humble accessibility label the consideration it deserves, instead relying on the Apple default behaviour. Secondly, they’re just some text, right? Who can get excited about just a boring old label? Well, I’m sure this won’t surprise you, but I can.

我觉得iOS上的辅助功能标签非常相似。 它们是可访问性在iOS上如何工作的基础，但是我认为它们存在一些PR问题。 首先，苹果公司在他们身上做得非常好，以至于我们经常不给不起眼的可访问性标签以应有的重视，而是依靠苹果公司的默认行为。 其次，它们只是一些文字，对不对？ 谁会为一个无聊的老唱片而兴奋？ 好吧，我相信这不会令您感到惊讶，但是我可以。

什么是辅助功能标签？ (What’s an Accessibility Label?)

When iOS presents your app’s interface to assistive technologies such as VoiceOver, Voice Control or Switch Control, it’s not passing your app’s screen, but a representation of the screen in what’s known as an accessibility tree, or accessible user interface as Apple often call it. Your customer’s chosen assistive technology will then handle how to present your interface in the way that best suits your customer. But assistive technologies need something to present, and their first port of call is your element’s accessibility label. VoiceOver will read it, braille displays will display it, and Voice Control will listen for it.

当iOS将您的应用程序界面显示为VoiceOver，Voice Control或Switch Control等辅助技术时，它不会通过您的应用程序屏幕，而是通过所谓的可访问性树或Apple经常称为的可访问用户界面来表示屏幕。 然后，客户选择的辅助技术将处理如何以最适合客户的方式显示界面。 但是辅助技术需要呈现一些东西，而它们的第一个调用端口是元素的可访问性标签。 VoiceOver会朗读它，盲文显示器将显示它，而Voice Control会监听它。

它只是工作 (It Just Works)

Here’s the first cool thing about accessibility labels on iOS. You don’t need to think about them. All of iOS’ inbuilt controls will work out what their accessibility label is from the content you’ve given it. Mostly this will be the control’s text value. Set this and you’re done.

这是关于iOS上的辅助功能标签的第一件事。 您无需考虑它们。 所有iOS内置控件都将根据您提供的内容确定其可访问性标签是什么。 通常，这将是控件的text值。 设置这个就可以了。

I’m not letting you get out of this post that easily though. Because although this behaviour is great, don’t think this absolves you of your responsibility for accessibility in your app. Most of the time this behaviour is fine, but why settle for fine when you make your app’s experience awesome?

不过，我不会轻易让您离开这篇文章。 因为尽管这种行为很好，但不要认为这免除了您对应用程序中可访问性的责任。 在大多数情况下，这种行为是可以的，但是当您使应用程序的体验变得很棒时，为什么还要满足呢？

自行设定 (Setting Your Own)

Sometimes you’ll need to specify an accessibility label yourself instead of relying on iOS to figure this out for you. Fortunately, doing that is just as simple as setting a text value. In code, you set the element’s accessibilityLabel property in UIKit, for SwiftUI use the .accessibility(label: )modifier. And in Interface Builder look out for the Accessibility section in the Identity Inspector pane.

有时，您需要自己指定一个可访问性标签，而不是依靠iOS来为您解决此问题。 幸运的是，这样做就像设置text值一样简单。 在代码中，您accessibilityLabel在UIKit中设置元素的accessibilityLabel属性，对于SwiftUI，请使用.accessibility(label: )修饰符。 在Interface Builder中，在Identity Inspector窗格中查找Accessibility部分。

// Setting an accessibility label to 'My accessibility label' in UIKitmyButton.accessibilityLabel = "My accessibility label"// Setting an accessibility label to 'My accessibility label' in SwiftUIButton(action: {}) {    Text("Button")}.accessibility(label: Text("My accessibility label"))

It’s important to remember that assistive technologies will only pick up your accessibility label if the element is visible to them. Again, Apple has made some sensible default choices on their UI elements for this value, but if you need to set an element to be visible or hidden to accessibility use the Accessibility Enabled checkbox in the screenshot above. Or for UIKit, isAccessibilityElement and the .accessibility(hidden: ) modifier in SwiftUI, both of these take a Boolean argument.

重要的是要记住，辅助技术只有在元素对他们可见的情况下才会出现。 同样，Apple在其UI元素上为此值做出了一些明智的默认选择，但是如果您需要将元素设置为可见或隐藏以显示可访问性，请使用上面的屏幕快照中的“已启用可访问性”复选框。 对于UIKit，在.accessibility(hidden: ) ， isAccessibilityElement和.accessibility(hidden: ) ：)修饰符都采用布尔参数。

// Hiding an image to assistive technologies in SwiftUIImage("Image")    .accessibility(hidden: true)// Revealing an image to assistive technologies in UIKitmyImage.isAccessibilityElement = true

下一个 (Next Up)

The next blog in this series is When to use Accessibility Labels

本系列的下一个博客是何时使用辅助功能标签

• iOS Accessibility Labels

  iOS辅助功能标签

• When to use Accessibility Labels

  何时使用辅助功能标签

• Writing Great iOS Accessibility Labels

  编写出色的iOS无障碍标签

• iOS Attributed Accessibility Labels

  iOS属性可访问性标签

This post was originally published on mobilea11y.com. Visit Mobile A11y for more mobile accessibility tools and techniques.

该帖子最初发布在mobilea11y.com上 。 访问Mobile A11y，以获取更多的移动辅助工具和技术。