李洪强iOS开发之宏定义方法来初始化一个单例对象

[b]单例的使用:[/b]



[b].m[/b]

为了方便实用，只要将以下代码定义在header文件或者.pch文件即可；

// .h

#define singleton_interface(class) + (instancetype)shared##class;

// .m

#define singleton_implementation(class) \

static class *_instance; \

\

+ (id)allocWithZone:(struct _NSZone *)zone \

{ \

static dispatch_once_t onceToken; \

dispatch_once(&onceToken, ^{ \

_instance = [super allocWithZone:zone]; \

}); \

\

return _instance; \

} \

\

+ (instancetype)shared##class \

{ \

if (_instance == nil) { \

_instance = [[class alloc] init]; \

} \

\

return _instance; \

}

使用方法：

Manager.h文件

#import <Foundation/Foundation.h>

@interface Manager :NSObject

singleton_interface(Manager);

@end

Manager.m文件

#import "Manager.h"

@interface Manager ()

@end

@implementation Manager

singleton_implementation(Manager)

@end

viewController调用

Manager *manager = [Manager sharedManager];