单例的宏定义实现-07-GCD 

 1 //
 2 //  LYHSingleTon.h
 3 //  07-单例的宏定义实现
 4 //
 5 //  Created by mac on 16/4/22.
 6 //  Copyright © 2016年 mac. All rights reserved.
 7 //
 8 
 9 #ifndef LYHSingleTon_h
10 #define LYHSingleTon_h
11 
12 // .h文件
13 
14 #define LYHSingleTonH + (instancetype)sharedInstance;
15 
16 // .m文件
17 
18 #define LYHSingleTonM \
19 /**
20  *  1. 创建一个全局变量,作用域比较广泛，所有的文件中都能够访问
21  */\
22 id _instance;\
23 \
24 /**
25  *  2. 重写allocWithZone：只分配一次内存
26  */\
27 + (instancetype)allocWithZone:(struct _NSZone *)zone {\
28     \
29     static dispatch_once_t onceToken;\
30     dispatch_once(&onceToken, ^{\
31         _instance = [super allocWithZone:zone];\
32     });\
33     return _instance;\
34 }\
35 /**
36  *  3. 既保证了单例（只分配一次内存），又保证了只init一次；
37  */\
38 + (instancetype)sharedInstance {\
39     \
40     static dispatch_once_t onceToken;\
41     dispatch_once(&onceToken, ^{\
42         _instance = [[self alloc] init];\
43     });\
44     return _instance;\
45 }\
46 /**
47  *  4. 重写copy方法
48  */\
49 - (id)copyWithZone:(NSZone *)zone {\
50     \
51     return _instance;\
52 }
53 
54 /**
55  *  下面是不添加注释的宏定义
56  */
57 ///*
58  
59 #define LYHSingleTonM \
60 id _instance;\
61 \
62 + (instancetype)allocWithZone:(struct _NSZone *)zone {\
63 \
64 static dispatch_once_t onceToken;\
65 dispatch_once(&onceToken, ^{\
66 _instance = [super allocWithZone:zone];\
67 });\
68 return _instance;\
69 }\
70 \
71 + (instancetype)sharedMusicTool {\
72 \
73 static dispatch_once_t onceToken;\
74 dispatch_once(&onceToken, ^{\
75 _instance = [[self alloc] init];\
76 });\
77 return _instance;\
78 }\
79 \
80 - (id)copyWithZone:(NSZone *)zone {\
81 \
82 return _instance;\
83 }
84  
85 */
86 
87 #endif /* LYHSingleTon_h */

 

posted on 2016-04-22 14:37  爱你久久iOS  阅读(197)  评论(0)  编辑  收藏  举报

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