分配时分配对象

发布于 2024-11-30 18:40:26 字数 1036 浏览 1 评论 0原文

我对 objc 非常陌生，我正在尝试尽可能多地了解内存管理并获得良好的例程。

我的问题是这样的代码是否危险（我喜欢短代码）

NSMutableArray *items = [[NSMutableArray alloc] init]; 

[items addObject:[[UIBarButtonItem alloc] 
                   initWithTitle:@"Login"
                   style:UIBarButtonItemStyleBordered
                   target:self 
                   action:@selector(tryUserInput)]];

[self.toolbar setItems:items animated:TRUE];
[self.view addSubview:self.toolbar];

[items release];

在示例中我可以发现人们总是创建他们添加到数组中的对象，添加它然后释放它。如果我分配它并同时添加它，数组会处理它，是吗？当我完成后我就会发布它。另外，我可以这样写吗？

self.navigationItem.backBarButtonItem = [[UIBarButtonItem 分配] initWithTitle:@"注销" 样式：UIBarButtonItemStyleDone 目标：无行动：无]；

或者我应该在那个上附加一个自动释放？

如果我理解正确的话，因为“navigationitem”是一个属性，它保留该对象并处理它。该数组保留了我添加到其中的所有对象。那么一切都应该没问题吗？

感谢您的帮助

原文

I am really new to objc and I am trying to understand as much as possible and get a good routine when it comes to mem management.

My question is if code like this is dangerous (i love short code)

NSMutableArray *items = [[NSMutableArray alloc] init]; 

[items addObject:[[UIBarButtonItem alloc] 
                   initWithTitle:@"Login"
                   style:UIBarButtonItemStyleBordered
                   target:self 
                   action:@selector(tryUserInput)]];

[self.toolbar setItems:items animated:TRUE];
[self.view addSubview:self.toolbar];

[items release];

In the examples I can find people always create the object that they add in the array, add it and then release it. If I alloc it and adds it at the same time, the array will take care of it aye? And I am releasing that when I'm done with it. Also, can I write it like this?

self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc]
initWithTitle:@"Logout"
style:UIBarButtonItemStyleDone
target:nil
action:nil];

Or should I attach an autorelease on that one?

If I understood it correclty, since the "navigationitem" is a property it retains the object and takes care of it. And the array retains all the objects I add to it. So everything should be fine?

Thanks for your help

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郁金香雨 2024-12-07 18:40:27

您需要将 autorelease 发送到 UIBarButton，否则就会发生泄漏。

当您分配它时，它的“保留计数”为+1；当你将它添加到数组时，它会变成+2。您需要它返回到+1，以便唯一的所有者将是数组，并且当数组被释放时，UIBarButton 将被释放。您可以通过两种方式完成此操作：

[items addObject:[[[UIBarButtonItem alloc] 
               initWithTitle:@"Login"
               style:UIBarButtonItemStyleBordered
               target:self 
               action:@selector(tryUserInput)] autorelease]];

或者

UIBarButtonItem *item = [[UIBarButtonItem alloc] 
               initWithTitle:@"Login"
               style:UIBarButtonItemStyleBordered
               target:self 
               action:@selector(tryUserInput)];
[items addObject:item];
[item release];

You need an to send an autorelease to the UIBarButton, or you'll have a leak.

When you alloc it, it has a "retain count" of +1; when you add it to the array it goes to +2. You need it to go back to +1, so that the only owner will be the array, and the UIBarButton will be deallocated when the array is freed. You can do it in two ways:

[items addObject:[[[UIBarButtonItem alloc] 
               initWithTitle:@"Login"
               style:UIBarButtonItemStyleBordered
               target:self 
               action:@selector(tryUserInput)] autorelease]];

UIBarButtonItem *item = [[UIBarButtonItem alloc] 
               initWithTitle:@"Login"
               style:UIBarButtonItemStyleBordered
               target:self 
               action:@selector(tryUserInput)];
[items addObject:item];
[item release];

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