iOS开发之单例使用（宏）

.h文件中

#define SKSingletonH(__className)\
+ (__className *)shareInstance;\


.m文件中
#define SKSingletonM(__className)\
\
static __className *_instance = nil;\
\
+ (__className *)shareInstance {\
static dispatch_once_t onceToken;\
dispatch_once(&onceToken, ^{\
_instance = [[self alloc] init];\
});\
return _instance;\
}\
\
+ (instancetype)allocWithZone:(struct _NSZone *)zone {\
static dispatch_once_t onceToken;\
dispatch_once(&onceToken, ^{\
_instance = [super allocWithZone:zone];\
});\
return _instance;\
}\
\
- (id)copy {\
return _instance;\
}\
\
- (id)mutableCopy {\
return _instance;\
}\