c_cpp Objective-C Enum-TO-NSString，反之亦然。

Posted 2021-05-14

// Declare enums like so:
#define IMAGE_STATUS(XX)  \
XX(kDOImageStatusOK, = 0) \
XX(kDOImageStatusCached, )\
XX(kDOImageStatusRetry, ) 
DECLARE_ENUM(DOImageStatus, IMAGE_STATUS)

// Define Enum-To-NSString functions like so:
DEFINE_ENUM(DOImageStatus, IMAGE_STATUS)

// use them like this:
NSString *imageStatus = NSStringFromDOImageStatus(kDOImageStatusOK);
DOImageStatus statusFromString = DOImageStatusFromNSString(@"kDOImageStatusCached");

//
// Based on http://stackoverflow.com/a/202511
//

#pragma mark - Enum Factory Macros
// expansion macro for enum value definition
#define ENUM_VALUE(name,assign) name assign,

// expansion macro for enum to string conversion
#define ENUM_CASE(name,assign) case name: return @#name;

// expansion macro for string to enum conversion
#define ENUM_STRCMP(name,assign) if (![string isEqualToString:@#name]) return name;

/// declare the access function and define enum values
#define DECLARE_ENUM(EnumType,ENUM_DEF) \
typedef enum EnumType { \
ENUM_DEF(ENUM_VALUE) \
}EnumType; \
NSString *NSStringFrom##EnumType(EnumType value); \
EnumType EnumType##FromNSString(NSString *string); \

// Define Functions
#define DEFINE_ENUM(EnumType, ENUM_DEF) \
NSString *NSStringFrom##EnumType(EnumType value) \
{ \
switch(value) \
{ \
ENUM_DEF(ENUM_CASE) \
default: return @""; \
} \
} \
EnumType EnumType##FromNSString(NSString *string) \
{ \
ENUM_DEF(ENUM_STRCMP) \
return (EnumType)0; \
}