iOS non-zero reference count in ARC and cannot dealloc

Question

Hi All

I am trying to dealloc a ViewController in ARC mode. However, the RefCount is always non-zero.

I have tried to set all object to nil and all subviews to removeFromSuperview + nil; and timer to invalidate + nil; still the counter = 2;

Is there a way to trace which pointer is still in retain?

Thanks

Answer 1

If you are using blocks you might also create retain cycle there. E.g. a block is referenced by an object and inside this block you are referencing object or calling instance method for object. Another option for retain count not dropping to 0 is that you have registered abject as observer for notification.

You might find this answer helpful: https://stackoverflow.com/a/12286739/2261423

Example of strong reference cycle from apple docs:

self.block = ^{
        [self doSomething];    // capturing a strong reference to self
                               // creates a strong reference cycle
    };