旋转时隐藏导航栏

- (void)setNavigationBarHidden:(BOOL)hidden animated:(BOOL)animated

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    [[self navigationController] setNavigationBarHidden:UIInterfaceOrientationIsLandscape(toInterfaceOrientation) animated:YES];
    [[UIApplication sharedApplication] setStatusBarHidden:UIInterfaceOrientationIsLandscape(toInterfaceOrientation) animated:YES];
}