Objectivec UIViewController 的 prefersStatusBarHidden 不起作用

我正在try 隐藏其中一个视图控制器的状态栏(以模式显示时).当我展示视图控制器时，状态栏将被隐藏，然后在关闭时返回.

我已经向显示的视图控制器添加了以下代码

- (BOOL)prefersStatusBarHidden
{
    return YES;
}

我还设置了信息中的键.plist文件到以下位置:

<key>UIViewControllerBasedStatusBarAppearance</key>
<true/>

据我所知，这应该是所有需要使这项工作.

我还使用一个自定义的动画控制器来做演示，这符合UIViewControllerAnimatedTransitioning协议.在animateTransition:实现中，我try 手动调用prefersStatusBarHidden，然后是setNeedsStatusBarAppearanceUpdate，以确保调用正在进行，但状态栏仍然存在.

如果您有任何关于为什么会发生这种情况的 idea ，我们将不胜感激.我已经搜索了StackOverflow，但似乎没有人遇到过这个问题，所有被接受的答案都指向拨打setNeedsStatusBarAppearanceUpdate，我已经在这么做了.

EDIT-下面的代码现在似乎符合要求

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
    if (self.isPresenting) {
        UIView *containerView = [transitionContext containerView];

        UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
        UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

        toViewController.view.frame = containerView.frame;

        [containerView addSubview:toViewController.view];

        // Ask the presented controller whether to display the status bar
        [toViewController setNeedsStatusBarAppearanceUpdate];

        [UIView animateWithDuration:1.0f delay:0.0f options:UIViewAnimationOptionCurveEaseIn animations:^{
            toViewController.view.alpha = 1.0f;
            fromViewController.view.alpha = 0.0f;
        } completion:^(BOOL finished) {
            [transitionContext completeTransition:YES];
        }];
    }
    else {
        // do the reverse
        UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
        UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

        [UIView animateWithDuration:1.0f delay:0.0f options:UIViewAnimationOptionCurveEaseIn animations:^{
            toViewController.view.alpha = 1.0f;
            fromViewController.view.alpha = 0.0f;
        } completion:^(BOOL finished) {
            [transitionContext completeTransition:YES];
            // Once dismissed - ask the presenting controller if the status bar should be presented
            [toViewController setNeedsStatusBarAppearanceUpdate];
        }];
    }
}

....

// PresentingController.m
- (BOOL)prefersStatusBarHidden
{
    if (self.presentedViewController) {
        return YES;
    }
    return NO;
}

// PresentedController.m
- (BOOL)prefersStatusBarHidden
{
    return YES;
}