Question

Inside of navigationController, when I’m in a ChildViewController and when the user taps on Back Button. I would love to send some data to the parentViewController before I go away.

Is any simple why to do this besides using

-(void)viewWillDisappear;

First, because this ChildViewController also has its own child, and when it gets pushed, viewWillDisappear gets called as well.

Second, when I user hits home button. it get called.(I guess)

Please, any reasonable and proper way to do this?

Answer 1

You can do this in any of following ways:

1. Send a notification when the second controller is going away and have the parent listen for it.

2. Create a delegate protocol that lets the second controller reference a parent method directly.

3. Use the parent’s viewWillAppear: and check the isMovingToParentViewController property for whether it’s just re-appearing.

and apply what is best for your value passing conditions and availability of values.