/** 在C页面的DisMiss方法里面添加一下代码(iOS6.0+) */
  if ([self respondsToSelector:@selector(presentingViewController)]){
    [self.presentingViewController.presentingViewController dismissViewControllerAnimated:YES completion:nil];
  }
  else {
    [self.parentViewController.parentViewController dismissViewControllerAnimated:YES completion:nil];
  }

/** 这里用到的核心处理办法是 */
/** 1.在A控制器模态Model推出B控制器的时候先给B控制器包装一个导航控制器 */
UINavigationController *ANavigationController = [[UINavigationController alloc] initWithRootViewController:[[BViewController alloc] init]];
[self presentViewController:ANavigationController animated:YES completion:nil];
/** 2.在B控制器遵守UINavigationControllerDelegate实现代理协议,隐藏当前控制器的导航栏 */
#pragma mark - UINavigationControllerDelegate
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated {
  // 判断要显示的控制器是否是自身控制器
  BOOL isShowMyController = [viewController isKindOfClass:[self class]];
  [self.navigationController setNavigationBarHidden:isShowMyController animated:YES];
}
#pragma mark - Push出C控制器
[self.navigationController pushViewController:[[CViewController alloc] init] animated:YES];
/** 3.在C控制器里面可直接在返回按钮方法里DisMiss */
[self.navigationController dismissViewControllerAnimated:YES completion:nil];