关联对象的内存管理

//
//  main.m
#import <Foundation/Foundation.h>
#import "Pet.h"
#import "Person.h"
#import "SuperMan.h"
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Person *per = [[Person alloc]init];
       [per test];
       NSUInteger r = [per retainCount];
        NSLog(@"%lu",r);
        [per release];
        
        
        SuperMan *sm = [[SuperMan alloc]init];
        Pet *pet = [[Pet alloc]init];
        [sm setPet:pet];
        [sm test];
        [sm release];
        [pet release];
    }
    return 0;
}

//
//  Person.h

#import <Foundation/Foundation.h>
#import "Pet.h"
@interface Person : NSObject
{
    Pet *_pet;//初始化
}
-(void)test;

@end
//
//  Person.m

#import "Person.h"

@implementation Person
-(instancetype)init{
    if (self=[super init]) {
        self->_pet = [[Pet alloc]init];
    }
    return self;
}
-(void)test{
    if (_pet) {
        [_pet play];
    }
}
-(void)dealloc{
    NSLog(@"释放");
    [_pet release];
    [super dealloc];
}
@end

//
//  Pet.h
//  关联对象的内存管理
#import <Foundation/Foundation.h>

@interface Pet : NSObject

-(void)play;
@end
//
//  Pet.m
//  关联对象的内存管理

#import "Pet.h"

@implementation Pet
-(void)play{
    NSLog(@"play");
}
-(void)dealloc{
    NSLog(@"Pet  释放");
  
    [super dealloc];
}
@end

//
//  SuperMan.h
#import <Foundation/Foundation.h>
#import "Pet.h"
@interface SuperMan : NSObject
{
    Pet *_pet;
}
-(void)setPet:(Pet*)mypet;
-(void)test;
@end
//
//  SuperMan.m

#import "SuperMan.h"

@implementation SuperMan
-(void)setPet:(Pet*)mypet{
    //_pet  = mypet;
    
    if (_pet!=mypet) {
        [_pet release];
        _pet = [mypet retain];
    }
}
-(void)test{
    if (_pet) {
        [_pet play];
    }
}
-(void)dealloc{
    NSLog(@"Super man 释放");
    [_pet release];
    [super dealloc];
}





@end