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])