何時/爲什麼/如何使用這些方法?何時/爲什麼/如何使用UINavigationControllerDelegate協議實例方法?
- navigationController:willShowViewController:animated:
– navigationController:didShowViewController:animated:
難道你不能只用這些UIViewController實例方法嗎?
– viewWillAppear:
– viewDidAppear:
– viewWillDisappear:
– viewDidDisappear: