Objective-C内存管理第七弹:ARC中@property的使用

//main.m

#import <Foundation/Foundation.h>
#import "Person.h"
//#import "Dog.h"

int main(int argc, const char * argv[]) {
    @autoreleasepool {


        Person * person = [[Person alloc] init];
        Dog * dog = [[Dog alloc] init];

        //把狗给人
        person.dog = dog;

        //把人给狗
        dog.person = person;
    }
    return 0;
}

//Person.h

#import <Foundation/Foundation.h>
#import "Dog.h"

/*内存管理:
  strong 对于普通对象
  copy   字符串
  assign 基本数据类型
  weak 循环引用一端必须使用weak
 */
@interface Person : NSObject

//年龄
@property (nonatomic, assign) int age;

//姓名
@property (nonatomic, copy) NSString * name;

@property (nonatomic, strong) Dog * dog;

@end

//Person.m

#import "Person.h"

@implementation Person

//ARC中不用再写dealloc方法中的[super dealloc]了，只需要验证对象是否被销毁了。

- (void)setDog:(Dog *)dog {

    _dog = dog;
}

- (void)dealloc
{

    NSLog(@"%s", __func__);
}

@end

//Dog.h

#import <Foundation/Foundation.h>
@class Person;

@interface Dog : NSObject

//当出现循环引用的时候，必须保证一端是weak的
@property (nonatomic, weak) Person * person;

@end

//Dog.m

#import "Dog.h"

@implementation Dog

- (void)setPerson:(Person *)person {

    _person = person;
}

- (void)dealloc
{
    NSLog(@"%s", __func__);
}

@end