如何限制目标C中枚举值的可见性？ [英] How to limit visibility of enum values in Objective C?

问题描述

在目标C中，在定义枚举时，所有枚举值都可以随处可见，并阻止全局命名空间。

我想让它成为Java-风格和强制枚举只能通过枚举类型名称访问，例如与

  typedef枚举
 {
 MONDAY，TUESDAY，WEDNESDAY，THURSDAY，FREDAY，SATURDAY，SUNDAY， NUM_OF 
}天; 
  

我想确保
只需调用 MONDAY 产生编译错误或至少是警告，访问枚举值的唯一方法是像$ code> Day.MONDAY 或 Day： ：MONDAY 或 [Day MONDAY] 或...

在Java中，我或者使用枚举或接口，但是这在Objective-C中是可行的吗？

如果没有，那么我必须命名所有的枚举，如下所示： DAY_MONDAY，DAY_TUESDAY ... ，以便在自动完成弹出窗口中轻松浏览。

解决方案

p>这只是一个解决方法，但是您可以使用多个类方法创建一个自定义界面（因此不需要创建一个实例），每个方法都代表一个常量。

这种方式的常量只有在你问的时候才可以访问（即 Day.MONDAY 或 [日MONDAY] ）。

In Objective C, when you define an enum, all of the enum values are visible everywhere and clog the global namespace.

I would like to make it Java-style and enforce that enums are only accessible thru the enum type name, e.g. with

typedef enum
{
MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY, NUM_OF
} Day;

I want to make sure that simply calling MONDAY produces compilation error or at least warning, and the only way to access the enum value were something like Day.MONDAY or Day::MONDAY or [Day MONDAY] or...

In Java I either use Enums or Interfaces, but is this doable in Objective-C?

If not, then I'd have to name all enums like this: DAY_MONDAY, DAY_TUESDAY... to make them easier to seach in auto-completion pop-up.

解决方案

It's just a workaround, but you can create a custom interface with a number of class methods (so that there's no need to create an instance), where each method represent a constant.

This way constants will be accessible only as you asked (ie. Day.MONDAY or [Day MONDAY]).

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