dispatch_queue_t的定义很强

Question

我看到以下一行：

@property (nonatomic, strong) dispatch_queue_t filterMainQueue;

为什么声明dispatch_queue_t的实例（不是对象）强大？

Answer 1

这是一个很好的做法。我想注意因为 OS X Mountain Lion和iOS 6.0，iOS / OS X运行时中的所有GCD和XPC对象现在被{{1}视为Objective-C对象它们现在不是原语，因此它们将像通常的Objective-C对象一样进行内存管理。这就是为什么从现在起你应该将它们声明为ARC。

您可以在strong：

中自行查看

object.h

docs中的{b>陈述：#define DISPATCH_DECL(name) OS_OBJECT_DECL_SUBCLASS(name, dispatch_object)

还有 iOS 6 and later—Dispatch objects (including queues) are Objective-C objects, and are retained and released automatically. OS X 10.8 and later—Dispatch objects (including queues) are Objective-C objects, and are retained and released automatically. Earlier versions—Dispatch objects are custom objects. You must handle the reference counting manually中的评论：

object.h