UIApplicationDelegate Event Function

## <UIApplicationDelegate> 애플리케이션 실행 완료 통지

애플리케이션이 실행 될 때 "실행 완료" 와 "애플리케이션 활성화" 두 가지 이벤트가 발생

    - (void) applicationDidFinishLaunching: (UIApplication *) app

 

## <UIApplicationDelegate> 애플리케이션 비활성화 통지

전화가 걸려오거나 메일 착신의 경우, 잠금상태일 경우 비활성화 상태가 되기 직전에 비활성화 이벤트가 발생.

    - (void) applicationWillResignActive: (UIApplication *) app

 

## <UIApplicationDelegate> 애플리케이션 활성화 통지

    - (void) applicationDidBecomeActive: (UIApplication *) app

 

## <UIApplicationDelegate> 애플리케이션 종료 직전 통지

홈 버튼이 눌러져서 애플리케이션이 종료되기 직전에도 이벤트가 발생 

애플리케이션의 설정값을 저장하는 등의 종료 처리를 수행, 나중에 실행했을 때 종료시의 상태로 되돌려 작업이나 게임을 계속해서 수행하고자 하는 애플리케이션 현재 상태를 보존

      - (void) applicationWillterminate: (UIApplication *) app