OC2_引用计数

//
//  Dog.h
//  OC2_引用计数
//
//  Created by zhangxueming on 15/6/18.
//  Copyright (c) 2015年 zhangxueming. All rights reserved.
//
 
#import <Foundation/Foundation.h>
 
@interface Dog : NSObject
{
    NSString *_name;
    NSInteger _age;
}
 
@property (copy, nonatomic) NSString *name;
@property (nonatomic)NSInteger age;
 
@end
 
//
//  Dog.m
//  OC2_引用计数
//
//  Created by zhangxueming on 15/6/18.
//  Copyright (c) 2015年 zhangxueming. All rights reserved.
//
 
#import "Dog.h"
 
@implementation Dog
 
@end

//
//  main.m
//  OC2_引用计数
//
//  Created by zhangxueming on 15/6/18.
//  Copyright (c) 2015年 zhangxueming. All rights reserved.
//
 
#import <Foundation/Foundation.h>
#import "Dog.h"
 
//管理内存方式:
//自动引用计数 automic refence counting
//手动引用计数 manual refence counting
 
//gar --> automic refence counting  yes --> no
 
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Dog *xiaoBai = [[Dog alloc] init];
 
        NSLog(@"retainCount = %li", xiaoBai.retainCount);
 
        //对对象进项保留, 增加对象的拥有权,使引用计数加1;
        //retain 的前提 是该对象存在
 
        Dog *xiaoHei = [xiaoBai retain];
        //Dog *xiaoHei = xiaoBai; 只是xiaohei的指针指向xiaobai ,并没有retainCount加1.
        NSLog(@"retainCount = %li", xiaoHei.retainCount);
 
        Dog *xiaoFei = [xiaoHei retain];
        NSLog(@"retainCount = %li", xiaoFei.retainCount);
 
        //release 释放对象拥有权, 引用计数器的值-1;
        [xiaoBai release];
        xiaoBai = nil;
        NSLog(@"retainCount = %li", xiaoFei.retainCount);
 
        [xiaoHei release];
        xiaoHei = nil;
        NSLog(@"retainCount = %li", xiaoFei.retainCount);
 
        [xiaoFei release];//retainCount = 0 dealloc
        xiaoFei = nil;
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
//        NSLog(@"今天天气不错, 就是下了点雨");
    //对象被释放之后, 不能再给对象发送消息
    // NSLog(@"retainCount = %li", xiaoFei.retainCount);
    }
    return ;
}