如何使 UIAppearance 代理适用于以编程方式创建的视图？
How to make UIAppearance proxies apply to programmatically created views?
我正在尝试使用 UIAppearance 为我的应用创建主题。
假设我希望我所有 UILabel 的文本都是橙色的。我写道：
UILabel.appearance(whenContainedInInstancesOf: [UIView.self]).textColor = .orange
但我意识到：
- 这适用于通过 Interface Builder 创建的每个
UILabel。
- 这不适用于任何以编程方式创建的
UILabel。它们默认显示为黑色
知道如何强制以编程方式创建的实例也变成橙色吗？
PS：我也试过：UILabel.appearance().textColor = .green这不是我想要的，但它也不起作用。
经过一番搜索...
显然，在 Interface Builder 中创建的 UI 个元素（例如标签） 受 .appearance() 设置并不是故意的，可能不可靠。
事实上，文档似乎相当混乱和误导。
To support appearance customization, a class must conform to the UIAppearanceContainer protocol and relevant accessor methods must be marked with UI_APPEARANCE_SELECTOR.
唯一采用 UIAppearance 协议的 class 是
UIBarItemUIView
唯一采用 UIAppearanceContainer 协议的 class 是
UIPopoverControllerUIPresentationControllerUIViewUIViewController
所以...最好的办法可能是 class 您的标签。
可在此处找到相关答案：
来自link：
"UIAppearance only allows you to set properties that are flagged with UI_APPEARANCE_SELECTOR in the Objective-C header file. Since UILabel has no such properties, it cannot be styled with UIAppearance"
也来自：https://developer.apple.com/documentation/uikit/uiappearance
"iOS applies appearance changes when a view enters a window, it doesn’t change the appearance of a view that’s already in a window. To change the appearance of a view that’s currently in a window, remove the view from the view hierarchy and then put it back."
也来自这里：trouble with UIAppearance and UIButton subclassing
"The reason it's working this way is because appearance properties are applied when the view is added to a view hierarchy, and nib-defined properties are applied before the view is added to a view hierarchy."
在以编程方式将该视图控制器添加到层次结构之前，我尝试在视图控制器的新 class 实例中设置标签的外观，但没有成功。
我正在尝试使用 UIAppearance 为我的应用创建主题。
假设我希望我所有 UILabel 的文本都是橙色的。我写道：
UILabel.appearance(whenContainedInInstancesOf: [UIView.self]).textColor = .orange
但我意识到：
- 这适用于通过 Interface Builder 创建的每个
UILabel。 - 这不适用于任何以编程方式创建的
UILabel。它们默认显示为黑色
知道如何强制以编程方式创建的实例也变成橙色吗？
PS：我也试过：UILabel.appearance().textColor = .green这不是我想要的，但它也不起作用。
经过一番搜索...
显然，在 Interface Builder 中创建的 UI 个元素（例如标签） 受 .appearance() 设置并不是故意的，可能不可靠。
事实上，文档似乎相当混乱和误导。
To support appearance customization, a class must conform to the UIAppearanceContainer protocol and relevant accessor methods must be marked with UI_APPEARANCE_SELECTOR.
唯一采用 UIAppearance 协议的 class 是
UIBarItemUIView
唯一采用 UIAppearanceContainer 协议的 class 是
UIPopoverControllerUIPresentationControllerUIViewUIViewController
所以...最好的办法可能是 class 您的标签。
可在此处找到相关答案：
来自link： "UIAppearance only allows you to set properties that are flagged with UI_APPEARANCE_SELECTOR in the Objective-C header file. Since UILabel has no such properties, it cannot be styled with UIAppearance"
也来自：https://developer.apple.com/documentation/uikit/uiappearance
"iOS applies appearance changes when a view enters a window, it doesn’t change the appearance of a view that’s already in a window. To change the appearance of a view that’s currently in a window, remove the view from the view hierarchy and then put it back."
也来自这里：trouble with UIAppearance and UIButton subclassing
"The reason it's working this way is because appearance properties are applied when the view is added to a view hierarchy, and nib-defined properties are applied before the view is added to a view hierarchy."
在以编程方式将该视图控制器添加到层次结构之前，我尝试在视图控制器的新 class 实例中设置标签的外观，但没有成功。