iOS single-case macro

First of all, a simple mention of a single-column concept, of course, the specific description may be benevolent see!
1. Single case design mode (Singleton)
1> What is a single column: it guarantees that the object created by a class will always be only 1

2> effect (why use)

• Save Memory overhead
• If there is some data, the whole program is used, only the same resources (to ensure that the data you access are the same, consistent)
• In general, the tool design is more appropriate for a single case model

3> How to achieve, the old programmer is encountering such a problem! There's less under arc!

• MRC (non-ARC)
• ARC

Cut the crap, take a look at my header file in single-case mode! Here the main is __has_feature (OBJC_ARC) judged whether it is arc, so the code looks a bit more!

Helps implement a single-case design pattern

Implementation of the. h file

Define SINGLETONH (MethodName) + (instancetype) shared# #methodName;

Implementation of the. m file

If __has_feature (OBJC_ARC)//Is arcDefine SINGLETONM (MethodName) \

Static id _instace = NIL; \

• (ID) Allocwithzone: (struct nszone *) zone \
  { \
  if (instace = = nil) {\
  Static dispatch_once_t Oncetoken; \
  Dispatch_once (&oncetoken, ^{\
  Instace = [Super Allocwithzone:zone]; \
  }); \
  } \
  return Instace; \
  } \
  \
• (ID) init \
  { \
  Static dispatch_once_t Oncetoken; \
  Dispatch_once (&oncetoken, ^{\
  Instace = [Super init]; \
  }); \
  return Instace; \
  } \
  \
• (instancetype) shared# #methodName \
  { \
  return [[Self alloc] init]; \
  } \
• (ID) Copywithzone: (struct nszone *) zone \
  { \
  return Instace; \
  } \
  \
• (ID) Mutablecopywithzone: (struct nszone *) zone \
  { \
  return Instace; \
  }

else//Not arcDefine SINGLETONM (MethodName) \

Static id _instace = NIL; \

• (ID) allocwithzone: (struct nszone *) zone \
  {\
  if ( instace = = nil) {\
  static dispatch_once _t Oncetoken; \
  Dispatch_once (&oncetoken, ^{\
  instace = [Super Allocwithzone:zone]; \
  }); \
  } \
  Return instace; \
  } \
  \
• (ID) init \
  {\
  static dispatch_once_t oncetoken; \
  Dispatch_once (&oncetoken, ^{ \
  instace = [super init]; \
  }; \
  return instace; \
  } \
  \
• (instancetype) shared# #m Ethodname \
  {\
  return [[Self alloc] init]; \
  } \
  \
• (oneway void) release \
  {\
  \
  } \
  \
• (ID) retain \
  {\
  return self; \
  } \
  \
• (nsuinteger) retaincount \
  {\
  return 1; \
  } \
• (ID) copywithzone: (struct nszone *) zone \
  {\
  return instace; \
  } \
  \
• (ID) mutablecopywithzone: (struct nszone *) zone \
  {\
  return instace; \
  }

endif

This is completely done, single-column all considerations, including copy case, multi-threading, and automatic judging arc and MRC situation!
Use only when you include the header file and then use the following
. h file: Singletonh (Httptool)
. m file: Singletonm (Httptool)

This thing who use who know!!!! Hee Hee Hope to be helpful to the reader!