IOS7内存释放问题 [英] IOS7 memory release issue

问题描述

我的IOS程序不是ARC，代码如下:

My IOS program is not ARC, code like this:

在 .h 文件中我定义了五个变量:

in the .h file i define five variables:

{
    UILabel *label1,*lable2;
    UIView *dwView;
    NSMutableArray *wordsArray;
}

.m 文件中的代码如下:

the code in the .m file like this:

- (void)viewDidLoad{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    viewArray=[[NSMutableArray alloc]init];
}

-(void)QuestionA{
    dwView=[[UIView alloc] initWithFrame:CGRectMake(20, 50, 975.0, 620)];

    label1 = [[UILabel alloc]initWithFrame:CGRectMake(10.0, 160.0, 950.0, 170.0)];
    label2 = [[UILabel alloc]initWithFrame:CGRectMake(30.0, 160.0, 950.0, 170.0)];

    [dwView addSubview:label1];
    [dwView addSubview:label2];

    [self.view addSubview:dwView];
    [viewArray addObject:dwView];

    [lable1 release];
    [lable2 release];
    [dwView release];
}

在我转向另一个活动之前，我注销了这些变量的保留计数:

before I turn to another activity I log out the retain count of those variables:

{
    [lable1 retainCount] ---> 2
    [lable2 retainCount] ---> 2
    [dwView retainCount] ---> 3
}

所以:我想知道为什么会这样，以及如何释放保留计数到 0?

So: I wonder why it like this, and how can I release the retain count to 0?

推荐答案

大概这些是在例程结束时调用release"之前的保留计数.

Presumably these are the retain counts before you call "release" at the end of your routine.

调用传统的 "alloc"/"init" 启动新实例化的对象，保留计数为 1.当您将 dwView 作为子视图添加到父视图时视图，这会增加保留计数.当您将 dwView 添加到数组时，也会增加保留计数.因此有 3 个.

Calling the traditional "alloc" / "init" starts the newly instantiated object off with a retain count of 1. When you add dwView as a subview to a parent view, that increments the retain count. When you add dwView to the array, that also increments the retain count. Hence 3 there.

对于标签也是如此，您已将它们添加为子视图，因此每个标签的保留计数增加 1(保留计数为 2).

Same for the labels, you've added them as subviews, so that increments the retain count by 1 for each (giving you a retain count of 2).

当保留计数达到零时，对象将被释放(例如，对于您的dwView"，这将是self.view"被释放时以及"viewArray`" 被释放).

The object will be released when the retain count hits zero (e.g. for your "dwView", that'll be when "self.view" is dealloc'd and when the "viewArray`" gets released).

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