iphone - self 保留在这个 Objective-C block 中吗？

Question

当我在 Objective-C 中有一个如下所示的 block 时:

self.request = [[ASIHTTPRequest requestWithURL:...

[self.longPollRequest setCompletionBlock:^{
    NSLog(@"%@", self.request.responseString);
}];

它会保留 self 还是显式保留 self.request？

Answer 1

作为Block Programming Topics说:

In a reference-counted environment, by default when you reference an Objective-C object within a block, it is retained. This is true even if you simply reference an instance variable of the object. Object variables marked with the __block storage type modifier, however, are not retained.

If you use a block within the implementation of a method, the rules for memory management of object instance variables are more subtle:

If you access an instance variable by reference, self is retained;

If you access an instance variable by value, the variable is retained.

你在 block 中引用了self，所以self被保留了。