从无导航页面导航进到下级页面，导航栏一闪而过，也很简单，再在压栈控制器里面再坐下处理，代码如下：
-(void)viewWillDisappear:(BOOL)animated{ [super viewWillDisappear:animated]; if (self.parentViewController.childViewControllers.count > 0) { [self.navigationController setNavigationBarHidden:YES animated:YES]; }else{ [self.navigationController setNavigationBarHidden:NO animated:YES]; } }
仅做记录！