enums - 如何将 typedef 枚举转换为 NSNumber？

Question

1. typedef enum 的每个值都被视为 int 吗？

   例如，给定以下typedef enum:

   // UIView.h
   
   typedef enum {
       UIViewAnimationCurveEaseInOut,
       UIViewAnimationCurveEaseIn,
       UIViewAnimationCurveEaseOut,
       UIViewAnimationCurveLinear
   } UIViewAnimationCurve;
   

   我如何知道使用哪种方法来创建 NSNumber？

   + (NSNumber *)numberWithShort:(short)value;
   + (NSNumber *)numberWithUnsignedShort:(unsigned short)value;
   + (NSNumber *)numberWithInt:(int)value;
   + (NSNumber *)numberWithUnsignedInt:(unsigned int)value;
   + (NSNumber *)numberWithLong:(long)value;
   + (NSNumber *)numberWithUnsignedLong:(unsigned long)value;
   + (NSNumber *)numberWithLongLong:(long long)value;
   + (NSNumber *)numberWithUnsignedLongLong:(unsigned long long)value;
   + (NSNumber *)numberWithInteger:(NSInteger)value NS_AVAILABLE(10_5, 2_0);
   + (NSNumber *)numberWithUnsignedInteger:(NSUInteger)value NS_AVAILABLE(10_5, 2_0);
   

   我认为 +[NSNumber numberWithInt:] 是正确的使用方法，因为 accepted answer to Best way to implement Enums with Core Data使用它。例如:

   [NSNumber numberWithInt:UIViewAnimationCurveLinear]
   

   但是，如果 +[NSNumber numberWithInt:] 是正确的，那为什么呢？

2. 对于按位枚举，例如:

   enum {
       UIViewAutoresizingNone                 = 0,
       UIViewAutoresizingFlexibleLeftMargin   = 1 << 0,
       UIViewAutoresizingFlexibleWidth        = 1 << 1,
       UIViewAutoresizingFlexibleRightMargin  = 1 << 2,
       UIViewAutoresizingFlexibleTopMargin    = 1 << 3,
       UIViewAutoresizingFlexibleHeight       = 1 << 4,
       UIViewAutoresizingFlexibleBottomMargin = 1 << 5
   };
   typedef NSUInteger UIViewAutoresizing;
   

   我猜测 +[NSNumber numberWithUnsignedInteger:] 是正确的使用方法，因为在 typedef 之后有一个显式的 NSUInteger。正确的？例如:

   [NSNumber numberWithUnsignedInteger:UIViewAutoresizingNone]
   

Answer 1

现在可以使用现代语法:

@(UIViewAnimationCurveLinear)