뒤로가기 스와이프 감지

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    if (navigationController.topViewController.transitionCoordinator) {
        [navigationController.topViewController.transitionCoordinator notifyWhenInteractionChangesUsingBlock:^(id<UIViewControllerTransitionCoordinatorContext> context) {
            if (context.isCancelled == NO) { // back 성공
               // do something...
            }
        }];
    }
}

 

참고: https://eeyatho.tistory.com/88?category=929245