OC ARC之循环引用问题（代码分析）

 1 //
 2 //  main.m
 3 //  03-arc-循环引用
 4 //
 5 //  Created by apple on 13-8-11.
 6 //  Copyright (c) 2013年 itcast. All rights reserved.
 7 //
 8 
 9 #import <Foundation/Foundation.h>
10 
11 @class Dog;
12 
13 @interface Person : NSObject
14 
15 @property (nonatomic, strong) Dog *dog;
16 
17 @end
18 
19 #import "Person.h"
20 
21 @implementation Person
22 
23 - (void)dealloc
24 {
25     NSLog(@"Person--dealloc");
26 }
27 
28 @end
29 
30 
31 #import <Foundation/Foundation.h>
32 
33 @class Person;
34 
35 @interface Dog : NSObject
36 
37 @property (nonatomic, weak) Person *person;
38 
39 @end
40 
41 #import "Dog.h"
42 
43 @implementation Dog
44 - (void)dealloc
45 {
46     NSLog(@"Dog--dealloc");
47 }
48 @end
49 
50 
51 
52 #import <Foundation/Foundation.h>
53 #import "Person.h"
54 #import "Dog.h"
55 
56 /*
57  当两端循环引用的时候，解决方案：
58  1> ARC
59  1端用strong，另1端用weak
60  
61  2> 非ARC
62  1端用retain，另1端用assign
63  */
64 
65 int main()
66 {
67     Person *p = [[Person alloc] init];
68     
69     
70     Dog *d = [[Dog alloc] init];
71     p.dog = d;
72     d.person = p;
73 
74     return 0;
75 }