Objective

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不熟悉单例的朋友,请先看Objective-C -- 单例设计模式

宏定义抽取单例,顾名思义,使用宏定义来替代单例的代码.这样我们以后写单例,有这个写好的单例代码的文件即可.

话不多少直接上代码.

这个文件保存的就是单例的代码,这里使用宏定义来替代这些代码

Singleton.h文件:// 以后就可以使用interfaceSingleton来替代后面方法的声明#define interfaceSingleton(name)  +(instancetype)share##name#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

Tools 文件

#import <Foundation/Foundation.h>#import "Singleton.h"@interface Tools : NSObject <NSCopying,NSMutableCopying>interfaceSingleton(Tools);@end@implementation ToolsimplementationSingleton(Tools)@end

Person 文件

#import <Foundation/Foundation.h>#import "Singleton.h"@interface Person : NSObjectinterfaceSingleton(Person);@end@implementation PersonimplementationSingleton(Person);@end

main文件

#import <Foundation/Foundation.h>#import "Tools.h"#import "Person.h"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];     Tools *t4 = [t3 copy];     Tools *t5 = [t3 mutableCopy];    NSLog(@"%p, %p, %p, %p, %p", t1, t2, t3, t4, t5);        Person *p1 = [Person sharePerson];    Person *p2 = [Person sharePerson];    NSLog(@"%p, %p", p1, p2);         // 如何判断当前是ARC还是MRC    // 可以在编译的时候判断当前是否是ARC#if __has_feature(objc_arc)    NSLog(@"ARC");#else    NSLog(@"MRC");#endif    return 0;}

输出结果:

2017-07-30 23:32:06.001955+0800 宏定义抽取单例[5759:221243] 0x100403420, 0x100403420, 0x100403420, 0x100403420, 0x1004034202017-07-30 23:32:06.002197+0800 宏定义抽取单例[5759:221243] 0x100303bd0, 0x100303bd02017-07-30 23:32:06.002215+0800 宏定义抽取单例[5759:221243] ARC

我把项目调成MRC后的输出结果:

2017-07-30 23:32:57.144990+0800 宏定义抽取单例[5783:221591] 0x100200160, 0x100200160, 0x100200160, 0x100200160, 0x1002001602017-07-30 23:32:57.145242+0800 宏定义抽取单例[5783:221591] 0x100500310, 0x1005003102017-07-30 23:32:57.145266+0800 宏定义抽取单例[5783:221591] MRC

这样就大功告成了,以后我们写单例.只需要Singleton.h文件即可.对ARC 和 MRC 项目都管用!

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