如何定义枚举字符串

enum DPodRecordType{
DPodRecordTypeA = 0,
DPodRecordTypeCNAME,
DPodRecordTypeMX,
DPodRecordTypeTXT,
DPodRecordTypeNS,
DPodRecordTypeAAAA,
DPodRecordTypeSRV,
DPodRecordTypeURL
};
typedef enum DPodRecordType DPodRecordType;
const NSArray *___DPodRecordType;
// 创建初始化函数。等于用宏创建一个getter函数
#define cDPodRecordTypeGet (___DPodRecordType == nil ? ___DPodRecordType = [[NSArray alloc] initWithObjects:\
@"A",\
@"CNAME",\
@"MX",\
@"TXT",\
@"NS",\
@"AAAA",\
@"SRV",\
@"URL", nil] : ___DPodRecordType)
// 枚举 to 字串
#define cDPodRecordTypeString(type) ([cDPodRecordTypeGet objectAtIndex:type])
// 字串 to 枚举
#define cDPodRecordTypeEnum(string) ([cDPodRecordTypeGet indexOfObject:string])