Tabbar

1. 首页显示tabbar，push其他页面后隐藏tabbar

ToViewController.hidesBottomBarWhenPushed=YES;

presentViewController时隐藏tabbar

UIViewController *presentedVC = [[UIViewController alloc]init];

presentedVC.modalPresentationStyle = UIModalPresentationOverCurrentContext;

AppDelegate *appdelegate=(AppDelegate*)[[UIApplication sharedApplication] delegate];

appdelegate.window.rootViewController.definesPresentationContext = YES;

[appdelegate.window.rootViewController presentViewController:presentedVC  animated:YES completion:nil];

UINavigationController

1. 根控制器隐藏NavigationBar，其他页面不隐藏或者部分隐藏NavigationBar

#pragma mark --- UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    if (![viewController isKindOfClass:[self class]]) {
        [navigationController setNavigationBarHidden:NO animated:animated];
    }
}

- (void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
    if ([viewController isKindOfClass:[self class]]) {
        [navigationController setNavigationBarHidden:YES animated:animated];
    }
}