MRC内存管理（二）数组、控件

来源：互联网发布：java 随机生成昵称编辑：程序博客网时间：2024/05/17 04:13

续上一篇MRC内存管理（一）

- (void)viewDidLoad {    [super viewDidLoad];    NSObject *obj = [[NSObject alloc] init];        NSLog(@"对象－－%lu",(unsigned long)obj.retainCount);            //当把对象放入数组中时，数组会对这个对象引用计数+1.    NSMutableArray *array = [[NSMutableArray alloc] initWithObjects:obj, nil];    NSLog(@"加入数组对象－－%lu",(unsigned long)obj.retainCount);            //把对象从数组中移除时，对象的引用计数-1.    [array removeObject:obj];    NSLog(@"移除数组对象－－%lu",(unsigned long)obj.retainCount);        //当数组本身被释放前，会对自己内部所有的对象release一次。        UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(20, 40, 200, 40)];    label.text = @"123";    NSLog(@"控件对象－－%lu",(unsigned long)label.retainCount);            //当把视图添加到父视图时，父视图会对这个视图retain一次。    [self.view addSubview:label];    NSLog(@"加入父视图－－%lu",(unsigned long)label.retainCount);            //当视图从父视图移除时，引用计数-1        //[label removeFromSuperview];            //当视图释放前，会对自身所有的子视图release一次    [label release];}- (IBAction)showAlertClick:(UIButton *)sender {    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"标题" message:@"消息" delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];    NSLog(@"alert－－%lu",(unsigned long)alert.retainCount);        //show会导致alert的引用计数增加。    [alert show];    NSLog(@"show－－%lu",(unsigned long)alert.retainCount);    [alert release];}- (IBAction)presentViewController:(UIButton *)sender {    SecondVC *vc = [[SecondVC alloc] init];    NSLog(@"创建VC－－%lu",(unsigned long)vc.retainCount);        //presentViewController模态弹出        //模态弹出会导致vc引用计数增加    [self presentViewController:vc animated:YES completion:nil];    NSLog(@"模态弹出－－%lu",(unsigned long)vc.retainCount);    [vc release];}

输出结果如下：

至于一个模态弹出为何输出引用计数这么大，博主也甚是不解，望广大友人给予帮忙解释一下，感激不尽，谢谢！

8 0