Ios 当显示视图时，画外音不会始终关注UILabel

我们有一个带有

UILabel

的登录屏幕，最初是隐藏的，用于在用户注销应用程序时表示消息

当在iOS中打开VoiceOver并且用户试图从应用程序注销时，VoiceOver最好能读出注销消息标签。相反，它读取登录屏幕的密码文本字段

注销按钮的操作具有以下实现代码

let loginStoryboard = UIStoryboard(name: "Login", bundle: nil)
        let loginViewController = loginStoryboard.instantiateInitialViewController() as! LoginViewController
        loginViewController.modalPresentationStyle = UIModalPresentationStyle.CurrentContext
loginViewController.logOut = true
self.presentViewController(loginViewController, animated: true, completion:nil)

注销指示器设置为显示注销消息标签。

LoginViewController

viewdiload

code

if(!logOut){
            self.logOutMsg.hidden = true
}else{
            self.logOutMsg.text = NSLocalizedString("LoggedOutMsg", comment: "Logged out message")
            self.logOutMsg.hidden = false
}

登录屏幕字段在故事板中启用了可访问性

行为不一致：有时读取注销消息标签，有时读取密码文本字段。 每当VoiceOver读取密码文本字段时，我可以在控制台日志中看到一个错误

 |error| Could not find <UIWindow: 0x124d13b10; frame = (0 0; 768 1024); gestureRecognizers = <NSArray: 0x174241140>; layer = <UIWindowLayer: 0x1742319c0>> in a list of sorted view [parent: <CaseworkerApp.AppDelegate: 0x124e008e0>] siblings (
        "<UILabel: 0x124d06cf0; frame = (132 1; 300 18); text = 'You are logged out of IBM...'; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x1742921b0>>",
        "<CaseworkerApp.LoginTextField: 0x124da4890; baseClass = UITextField; frame = (80 37; 330 50); text = ''; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x1704551e0>; layer = <CALayer: 0x175033de0>>",
        "<CaseworkerApp.LoginTextField: 0x124d9bd50; baseClass = UITextField; frame = (80 110; 330 50); text = ''; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; tag = 1; gestureRecognizers = <NSArray: 0x17044dfb0>; layer = <CALayer: 0x175227ce0>>",
        "<UIButton: 0x124d52900; frame = (80 183; 330 50); autoresize = RM+BM; layer = <CALayer: 0x175039ae0>>"
    ).  If this happened right around a screen change, it might be okay, but otherwise this is probably a bug.
    2015-08-10 16:46:50.108 CaseworkerApp[2217:479225] |error| Could not find <UIWindow: 0x124d13b10; frame = (0 0; 768 1024); gestureRecognizers = <NSArray: 0x174241140>; layer = <UIWindowLayer: 0x1742319c0>> in a list of sorted view [parent: <CaseworkerApp.AppDelegate: 0x124e008e0>] siblings (
        "<UILabel: 0x124d06cf0; frame = (132 1; 300 18); text = 'You are logged out of IBM...'; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x1742921b0>>",
        "<CaseworkerApp.LoginTextField: 0x124da4890; baseClass = UITextField; frame = (80 37; 330 50); text = ''; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x1704551e0>; layer = <CALayer: 0x175033de0>>",
        "<CaseworkerApp.LoginTextField: 0x124d9bd50; baseClass = UITextField; frame = (80 110; 330 50); text = ''; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; tag = 1; gestureRecognizers = <NSArray: 0x17044dfb0>; layer = <CALayer: 0x175227ce0>>",
        "<UIButton: 0x124d52900; frame = (80 183; 330 50); autoresize = RM+BM; layer = <CALayer: 0x175039ae0>>"
    ).  

| error |在排序视图[父项：]的列表中找不到(
"",
"",
"",
""
).如果这正好发生在屏幕更改附近，可能没问题，但否则这可能是一个错误。
2015-08-10 16:46:50.108 CasewerApp[2217:479225]|错误|在排序视图[父项：]的列表中找不到(
"",
"",
"",
""
).  

如果这发生在屏幕更改的附近，可能没什么问题，但除此之外，这可能是一个bug

---

请提供任何帮助以解决此问题？

当显示视图时，VoiceOver将从辅助功能树中的第一个元素开始读取。可能有两种解决方案

首先，您可以修改订单

其次，当视图发生变化时，您可以通过发布UIAccessibility的ScreenChanged通知，指示VoiceOver应该关注哪个元素，从而使VoiceOver关注某个特定元素

UIAccessibility.post(notification:.screenChanged, argument:elementToBeFocussed)

阅读文档中的更多信息

UIAccessibility.post：

11.通知：

屏幕更改：