首页 导航栏隐藏 下一级页面显示，pop回来遇到的问题

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self.navigationController setNavigationBarHidden:NO animated:animated];
    
}

- (void)viewWillDisappear:(BOOL)animated {
    self.navigationController.navigationBarHidden = YES;
    [super viewWillDisappear:animated];
}