子视图和超级视图之间的iOS参考关系

Question

In the iOS documentation, it seems that subview has a strong reference to superview:

@property(nonatomic, readonly) UIView *superview

The default for property is strong . As we all know, superview has a strong reference to subview, so is there a reference cycle between superview and subview?

Answer 1

Yes, there is a reference cycle. To get rid of a view, you have to call [theView removeFromSuperview] which breaks the cycle.

Answer 2

No, the default is assign . That's roughly the same as unsafe-unretained.

Answer 3

There won't be any reference cycle. When superview is deleted, it will delete all its children first before deleting itself. If you just want to delete current view, you can do it. Superview don't object.