弱引用难题

Question

Suppose I want to create a weak reference so it will not be retained by a block. So I have a property:

@property (nonatomic, strong) MyClass *myObject;

and I do this:

__weak typeof(self.myObject) myObjectWeak = self.myObject;

void (^doSomething)() = ^void() {
   [myObjectWeak doSomething];    
};

but what about this:

__weak typeof(self) selfWeak = self;

void (^doSomething)() = ^void() {
   [selfWeak.myObject doSomething];    
};

Will this produce the same effect? I mean having a weak reference to myObject inside the block? I suspect it is not, but I just need to confirm.

Answer 1

Yes, using selfWeak in that last example is sufficient to break the strong reference cycle. Don't worry about the fact that you reference its properties in there.