52가지 유효한 방법(5) - 상태, 옵션, 상태 코드를 매거로 표시

열거(enum)

NSENUM 및 NSOPTIONS 매크로는 열거 유형을 정의하고 기본 데이터 유형을 나타냅니다.

/* NS_ENUM supports the use of one or two arguments. The first argument is always the integer type used for the values of the enum. The second argument is an optional type name for the macro. When specifying a type name, you must precede the macro with 'typedef' like so:
 
typedef NS_ENUM(NSInteger, NSComparisonResult) {
    ...
};
 
If you do not specify a type name, do not use 'typedef'. For example:
 
NS_ENUM(NSInteger) {
    ...
};
*/
 
#define NS_ENUM(...) CF_ENUM(__VA_ARGS__)

#define NS_OPTIONS(_type, _name) CF_OPTIONS(_type, _name)

열거(Enum) 및 상태(states)

typedef NS_ENUM(NSInteger, UIViewAnimationTransition) {
    UIViewAnimationTransitionNone,
    UIViewAnimationTransitionFlipFromLeft,
    UIViewAnimationTransitionFlipFromRight,
    UIViewAnimationTransitionCurlUp,
    UIViewAnimationTransitionCurlDown,
};

매거(enum)와 옵션(options)

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

UIViewAutoresizingNone                            0 0 0 0 0 0 0 0
UIViewAutoresizingFlexibleLeftMargin              0 0 0 0 0 0 0 1
UIViewAutoresizingFlexibleWidth                   0 0 0 0 0 0 1 0
UIViewAutoresizingFlexibleRightMargin             0 0 0 0 0 1 0 0
UIViewAutoresizingFlexibleTopMargin               0 0 0 0 1 0 0 0
UIViewAutoresizingFlexibleHeight                  0 0 0 1 0 0 0 0
UIViewAutoresizingFlexibleBottomMargin            0 0 1 0 0 0 0 0
UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight 
                                                  0 0 0 1 0 0 1 0

매거(enum)와 상태 코드(codes)

typedef NS_ENUM(NSUInteger, EOCConnectionState) {
    EOCConnectionStateDisconnected,
    EOCConnectionStateConnecting,
    EOCConnectionStateConnected
};

switch (_currentState) {
    EOCConnectionStateDisconnected:
      //...
      break;
    EOCConnectionStateConnecting:
      //...
      break;
    EOCConnectionStateConnected:
      //...
      break;
}

요점