UIAppearance 的“当不包含在"时
问题说明
我目前正在构建一个复杂的 UIAppearance 修饰符网络*，并且遇到了一个问题.
I am currently spinning a complex web of UIAppearance modifiers*, and have come across a problem.
我使用 FlatUIKit 的自定义 UIBarButton 外观协议导致 MFMailComposerViewController 抱怨并停止工作.
My usage of FlatUIKit's custom UIBarButton appearance protocol is causing MFMailComposerViewController to complain and stop working.
因此，不是使用 UIAppearance 的 whenContainedIn 方法来指定导致发生修改的类，而是有没有办法排除某些类，即when not包含在?
Therefore, instead of using UIAppearance's whenContainedIn method to specify classes that cause modification to occur, is there a way to exclude certain classes, i.e. a "when not contained in"?
*我说的是 UIAppearance 协议，该协议用于在应用的委托中预定义对象外观设置.
*I am talking about the UIAppearance protocol that is used to predefine object appearance settings in the app's delegate.
正确答案
您可以使用 appearanceWhenContainedIn: 指定 nil 修改，这将给出默认外观:
You can use appearanceWhenContainedIn: to specify nil modification, which will give the default appearance:
[[UIBarButton appearance] setBarTintColor:[UIColor redColor]];
[[UIBarButton appearanceWhenContainedIn:[MFMailComposerViewController class], nil] setBarTintColor:nil];
从 iOS 9 SDK 开始，还有
As of iOS 9 SDK, there is also
[[UIBarButton appearance] setBarTintColor:[UIColor redColor]];
[[UIBarButton appearanceWhenContainedInInstancesOfClasses:@[[MFMailComposerViewController class]] setBarTintColor:nil];
可以像这样使用 Swift-2:
Which can be used Swift-2 like so:
UIBarButton.appearance().barTintColor = UIColor.redColor()
UIBarButton.appearanceWhenContainedInInstancesOfClasses([MFMailComposerViewController.self]).barTintColor = nil
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