使用“保留”的对象泄漏
我有一个用保留属性定义的属性，我正在合成它：
@property (nonatomic, retain) UISwitch *mySwitch;
在我的 loadView 中我正在这样做：
self.mySwitch = [[UISwitch alloc] initWithFrame:CGRectMake(0, 0, 40, 20)];
最后在我的 dealloc 中我正在这样做：
self.mySwitch = nil;
我是否泄漏了这个对象（mySwitch），因为我使用了一个分配？我应该在分配框架时自动释放它吗？
请建议。
I have a property defined with retain attribute which I am synthesizing:
@property (nonatomic, retain) UISwitch *mySwitch;
And inside my loadView I am doing this:
self.mySwitch = [[UISwitch alloc] initWithFrame:CGRectMake(0, 0, 40, 20)];
And finally inside my dealloc I am doing this:
self.mySwitch = nil;
Am I leaking this object (mySwitch) as I have used one alloc? Should I autorelease it while assigning it frame?
Please suggest.
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该行：
实际上调用retain两次 - 一次用于
alloc，并在对self.mySwitch（这是您已经拥有的属性）的赋值中再次调用指定的应该保留分配给它的任何值。）我被告知最好的修复是在线上添加对autorelease的调用，使其：The line:
Actually calls retain twice- once for the
allocand again in the assignment toself.mySwitch(which is a property you've specified shouldretainany values assigned to it.) The fix I have been told is best is to add a call toautoreleaseon the line, making it:是的，你正在泄漏。您正在使用
+alloc/-initWithFrame:创建一个拥有的对象，然后将该拥有的对象分配给标记为retain的属性。这将创建对该对象的第二个拥有的引用。此时，您泄漏了原始拥有的引用，这导致对象本身泄漏。这里正确的行为是在将对象分配给属性之前调用
-autorelease。顺便说一句，不建议您访问
-dealloc内部的属性。通常给出的两个原因是 1) 这将广播 KVO 通知，您不希望在-dealloc内部发送该通知，2) 如果有人覆盖 setter（在此类或子类中）它可能无法正常工作。推荐的方法是简单地释放底层 ivar，因此您会看到类似以下内容：在其他地方将 nil 分配给该属性是完全安全的（并且推荐）。
Yes, you are leaking. You are creating an owned object with
+alloc/-initWithFrame:, then assigning that owned object to a property markedretain. This creates a second owned reference to the object. At this point, you leak your original owned reference, which causes the object itself to leak.The correct behavior here is to call
-autoreleaseon the object before assigning it to the property.On a tangential note, it's not recommended that you access properties inside of
-dealloc. The two reasons generally given for this are 1) this will broadcast KVO notifications, which you don't want inside of-dealloc, and 2) if anyone overrides the setter (in this class or a subclass) it may not behave properly. The recommended approach is to simply release the underlying ivar, so you'd see something like the following instead:Assigning nil to the property is perfectly safe (and recommended) everywhere else.
作为自动释放的替代方案，如果您需要更严格的内存管理，这应该适合您：
稍后例如在 dealloc 中
As alternative to autorelease, if you need a tighter memory management this should work for you:
and later e.g. in dealloc
是的。你正在泄漏对象。请记住这里的一个简单规则：
如果您使用了
+alloc，则始终必须有相应的-release。Yes. You are leaking object. Remember one simple rule here:
if you used
+allocthere is always must be corresponding-release.