pragma mark 宏定义抽取单例
pragma mark 概念
pragma mark 代码
#import <Foundation/Foundation.h>
#pragma mark 类
#import "Tools.h"
#import "Person.h"
#pragma mark main函数
int main(int argc, const char * argv[])
{
Tools *t1 = [[Tools alloc]init]; // 内部 会调用 allocWithZone
Tools *t2 = [Tools new]; // [ [alloc] init] // allocWithZone
Tools *t3 = [Tools shareTools];
NSLog(@" %p %p %p",t1,t2,t3);
Tools *t4 = [t3 copy];
Tools *t5 = [t3 mutableCopy];;
NSLog(@"%p %p %p %p %p",t1,t2,t3,t4,t5);
NSLog(@"------1.end -------");
Person *p1 = [Person sharePerson];
Person *p2 = [Person sharePerson];
Person *p3 = [Person sharePerson];
NSLog(@"%p ,%p, %p",p1,p2,p3);
// 如何判断 当前是ARC 还是 MRC
// 可以在编译的时候, 判断当前 是不是 ARC
#pragma mark - 在编译的时候 判断当前 是不是 ARC
#if __has_feature(objc_arc)
NSLog(@"ARC");
#else
NSLog(@"MRC");
#endif
return 0;
}
Tools.h //工具类
#import <Foundation/Foundation.h>
#import "Singleton.h"
@interface Tools : NSObject <NSCopying,NSMutableCopying>
// share + 当前的类名
//+ (instancetype)shareTools;
interSingleton(Tools);
@end
Tools.m
#import "Tools.h"
@implementation Tools
/*
+ (instancetype)shareTools
{
Tools *instance = [[self alloc]init];
return instance;
}
static Tools * _instance = nil;
+ (instancetype)allocWithZone:(struct _NSZone *)zone
{
// 以下 代码 在多线程中 也能保证只执行一次
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_instance = [[super allocWithZone:zone]init];
});
return _instance;
}
- (id)copyWithZone:(NSZone *)zone
{
return _instance;
}
- (id)mutableCopyWithZone:(NSZone *)zone
{
return _instance;
}
#pragma mark MRC (才需要下面几行代码) //需要编译的时候 动态的 判断 当前是ARC 还是 MRC
- (oneway void)release
{
}
- (instancetype)retain
{
return _instance;
}
- (NSUInteger)retainCount
{
return MAXFLOAT;
}
*/
implementationSingleton(Tools)
@end
Person.h //人类
#import <Foundation/Foundation.h>
#import "Singleton.h"
@interface Person : NSObject
interSingleton(Person);
@end
Person.m
#import "Person.h"
@implementation Person
implementationSingleton(Person)
@end
Singleton.h //单例宏的文件.h
// 用 A 替换 B
//#define A B
// 以后 就可以使用 interSingleton 来代替后面的方法声明
//#define interSingleton + (instancetype)shareTools;
#pragma 1. - 定义 单例 宏的声明
// 传递一个参数的 宏定义 [宏的参数 用(xxx) 替代的参数用## xxx ]
#define interSingleton(name) + (instancetype)share##name
#pragma 2. - 定义 单例 宏的视线
// 使用 \ 反斜杠 就是换行 说明 下一行 也是注释
#if __has_feature(objc_arc)
// ARC
#define implementationSingleton(name) \
+ (instancetype)share##name \
{ \
name *instance = [[self alloc]init]; \
return instance; \
} \
static name * _instance = nil; \
+ (instancetype)allocWithZone:(struct _NSZone *)zone \
{ \
static dispatch_once_t onceToken; \
dispatch_once(&onceToken, ^{ \
_instance = [[super allocWithZone:zone]init]; \
}); \
return _instance;\
} \
- (id)copyWithZone:(NSZone *)zone \
{ \
return _instance; \
}\
- (id)mutableCopyWithZone:(NSZone *)zone \
{ \
return _instance; \
} \
#else
// MRC
#define implementationSingleton(name) \
+ (instancetype)share##name \
{ \
name *instance = [[self alloc]init]; \
return instance; \
} \
static name * _instance = nil; \
+ (instancetype)allocWithZone:(struct _NSZone *)zone \
{ \
static dispatch_once_t onceToken; \
dispatch_once(&onceToken, ^{ \
_instance = [[super allocWithZone:zone]init]; \
}); \
return _instance;\
} \
- (id)copyWithZone:(NSZone *)zone \
{ \
return _instance; \
}\
- (id)mutableCopyWithZone:(NSZone *)zone \
{ \
return _instance; \
} \
- (oneway void)release \
{ \
} \
- (instancetype)retain \
{ \
return _instance; \
} \
- (NSUInteger)retainCount \
{ \
return MAXFLOAT; \
} \
#endif
