宏定义常见用法

#define StrParam(param) @#param
#define DictionaryKV(enumKey) StrParam(enumKey):@#enumKey,
#define TEST 2
static NSMutableDictionary *convertor;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
    convertor = [NSMutableDictionary dictionaryWithDictionary:@{
                                                                DictionaryKV(TEST)
                                                                }];
});