Question

我在swift中使用Util类作为帮助类。除了函数，我想用自定义颜色实现一些常量。

以这种方式使用Struct是否正确？

class Util: NSObject {

struct Colors {
    static let white = UIColor(red: 1, green: 1, blue: 1, alpha: 1)
    static let orangeCantaloupe = UIColor(red: 1, green: 204/255, blue: 102/255, alpha: 1)
    static let greyMercury = UIColor(red: 230/255, green: 230/255, blue: 230/255, alpha: 1)
    static let greyMagnesium = UIColor(red: 179/255, green: 179/255, blue: 179/255, alpha: 1)

}

class func anyFunction() {

.......
 }
}

Answer 1

您可以用新颜色扩展UIColor：

extension UIColor {
   static let white = UIColor(red: 1, green: 1, blue: 1, alpha: 1)
   static let orangeCantaloupe = UIColor(red: 1, green: 204/255, blue: 102/255, alpha: 1)
   static let greyMercury = UIColor(red: 230/255, green: 230/255, blue: 230/255, alpha: 1)
   static let greyMagnesium = UIColor(red: 179/255, green: 179/255, blue: 179/255, alpha: 1)
}

在期望使用UIColor的情况下，可以隐含该类型，因此您可以只写something.color = .orangeCantaloupe

或者，您可以将它们保留在单独的名称空间中（为了方便说明），例如BrandColors。空枚举效果最好，所以您知道没有人会意外地实例化一个毫无意义的对象。

Answer 2

这是枚举的工作。

struct Colors {
    case white(UIColor(red: 1, green: 1, blue: 1, alpha: 1))
    case orangeCantaloupe(UIColor(red: 1, green: 204/255, blue: 102/255, alpha: 1))
    case greyMercury(UIColor(red: 230/255, green: 230/255, blue: 230/255, alpha: 1))
    case greyMagnesium(UIColor(red: 179/255, green: 179/255, blue: 179/255, alpha: 1))
}

在Swift中为全局常量的类内部构造

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