保留核心基金会财产 [英] Retained Core Foundation Property
问题描述
（Xcode 4.2，iOS 5， ARC ）
(Xcode 4.2, iOS 5, ARC)
我有一些属性应该取得所有权的Core Foundation（/ Graphics）对象他们的对象。现在在这些 Apple docs 我发现了这个：
I have some properties of Core Foundation (/Graphics) objects that should take ownership of their objects. Now in these Apple docs I found this:
在OS X v10.6及更高版本中，你可以使用__attribute__关键字指定应将Core Foundation属性视为
用于内存管理的Objective-C对象：
@property（retain）__ attribute __（（NSObject））CFDictionaryRef myDictionary ;
不幸的是我找不到任何详细说明。我正在使用它：
Unfortunately I couldn't find any elaboration on this. I'm using this:
@property（nonatomic，strong）__ attribute __（（NSObject））CGImageRef loupeImage;
它看起来像我期望的那样。它保留了设置属性的对象，并在我将属性设置为nil时将其释放。
And it seems to work the way I'd expect. It retains the object on setting the property and releases it when I set the property to nil.
现在我的问题是，我是否还需要将这些属性显式设置为nil在我的dealloc？
Now my question is, do I still need to explicitly set those properties to nil in my dealloc?
推荐答案
编辑：我以前的帖子不正确。属性上的 __ attribute __（（NSObject））仅在使用属性访问器时使其保留/释放属性。它不会影响对ivar的访问，特别是它不会在 dealloc 中删除（或释放）该属性。所以，是的，在您的 dealloc 中，您需要说 self.loupeImage = nil; 或者您需要说 [_ loupeImage release] 。
My previous post was incorrect. __attribute__((NSObject)) on the property only causes it to retain/release the property when using the property accessors. It does not affect access to the ivar, and notably, it does not nil out (or release) the property in dealloc. So yes, in your dealloc you either need to say self.loupeImage = nil; or you need to say [_loupeImage release].
原帖：
如果编译器接受 strong 关键字，那么它将正确处理它，保留并释放为预期，并在ARC中自动终止。 __ attribute __（（NSObject））的整个想法是告诉编译器将此对象完全视为obj-c对象，这就是它的作用。
If the compiler accepts the strong keyword, then it's going to treat it correctly, retaining and releasing as expected, and nilling out automatically in ARC. The whole idea of __attribute__((NSObject)) is it tells the compiler to treat this object exactly as if it were an obj-c object, and so that's what it does.
所以不，你不应该在dealloc中明确地将它们取出来。您将自动获得nilling / release的默认ARC行为。
So no, you shouldn't have to explicitly nil them out in dealloc. You'll get the default ARC behavior of nilling/releasing automatically.
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