I have a view hierarchy like this:
nav1 (UINavigationController, top level object in nib)
view1 (UIViewController)
nav2 (UINavigationController, top level object in nib)
view2 (UIViewController)
I called nav2's view[Will/Did][Appear/Disappear] methods in view1's each method. and when I'm calling presentModalViewController:animated to display nav2 & view2, view2' viewDidAppear called twice.
I treated viewDidAppear will occur only once for a single present/dismiss/push/pop, however I can't know how understand this.