调用后调整导航栏 完成转换:在自定义转换中

Question

我的目标是为用户提供缩放模式转换，从类似于启动应用程序时跳板图标放大的视图。

呈现的视图控制器正确放大，但导航栏在状态栏下的位置错误。此位置在调用 [transitionContext completeTransition：done]; 后得到纠正。如何从过渡开始就使其正确？

这是错误的屏幕录像：http://youtu.be/7LKU4lzb-uw（故障在录音的第6秒）

UIViewControllerAnimatedTransitioning 代码：

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    UIView *container = [transitionContext containerView];
    CGPoint viewCenter = self.view.center;
    CGSize viewSize = self.view.frame.size;
    CGSize controllerSize = toViewController.view.frame.size;
    CGFloat controllerFromX = viewCenter.x - (controllerSize.width / 2);
    CGFloat controllerFromY = viewCenter.y - (controllerSize.height / 2);
    CGAffineTransform transform = CGAffineTransformMakeTranslation(controllerFromX, controllerFromY);
    transform = CGAffineTransformScale(transform, viewSize.width / controllerSize.width, viewSize.height / controllerSize.height);
    if (self.reverse) {
        [container insertSubview:toViewController.view belowSubview:fromViewController.view];
    } else {
        toViewController.view.transform = transform;
        [container addSubview:toViewController.view];
    }
    [UIView animateKeyframesWithDuration:ZoomTransitioningDuration 
                                   delay:0 
                                 options:0 
                              animations:^{
                if (self.reverse) {
                    fromViewController.view.alpha = 0.0f;
                    fromViewController.view.transform = transform;
                } else {
                    toViewController.view.transform = CGAffineTransformIdentity;
                }
        } 
                              completion:^(BOOL finished) {
                [transitionContext completeTransition:finished];
        }];
}

Answer 1

问题是您在将目标视图控制器的视图插入容器之前设置转换。

切换顺序应该可以解决它：

if (self.reverse) {
    [container insertSubview:toViewController.view belowSubview:fromViewController.view];
} else {
    [container addSubview:toViewController.view];
    toViewController.view.transform = transform;
}

请参阅此处的第 4 点。由于在将导航控制器的视图作为子视图插入之前已应用转换，因此布局引擎不会认为导航栏位于窗口的顶部边缘，因此无需进行调整以避免状态栏。

Answer 2

我找到了一个解决方案，虽然很黑客。在动画开始之前，我必须手动调整导航栏帧：

if (self.reverse) {
    [container insertSubview:toViewController.view belowSubview:fromViewController.view];
} else {
    toViewController.view.transform = transform;
    [container addSubview:toViewController.view];
    // fix navigation bar position to prevent jump when completeTransition: is called
    if ([toViewController isKindOfClass:[UINavigationController class]]) {
        UINavigationController* navigationController = (UINavigationController*) toViewController;
        UINavigationBar* bar = navigationController.navigationBar;
        CGRect frame = bar.frame;
        bar.frame = CGRectMake(frame.origin.x, frame.origin.y + 20.0f, frame.size.width, frame.size.height);
    }
}

Answer 3

首先将 toViewControllerView 添加到 ContainerView，然后设置 toViewControllerView 转换，如下所示。

[container addSubview：toViewController.view];

toViewController.view.transform = transform;

这将解决问题。

Answer 4

这仍然是一个黑客，基于 Ondřej Mirtes 的一个，但如果你有一个通话状态栏并且你在 iOS8 上，它会更好

用

if([toViewController isKindOfClass:[UINavigationController class]]) { 
  UINavigationController *navCtrl = (UINavigationController *)toViewController;
  UINavigationBar *navBar = navCtrl.navigationBar;
  if(navBar.frame.origin.y == 0 && navBar.frame.size.height == 44) {
    navBar.frame = CGRectMake(0, 0, navBar.frame.size.width, fmin(44 + [UIApplication sharedApplication].statusBarFrame.size.height, 64)); 
  }
}

虽然仍然很丑：/