Question

我使用iOS 7引入的新自定义过渡，我试图将视图从“主”视图控制器移动到我的“详细信息”视图控制器中的视图，类似于Photos.app放大的方式点击它时的照片，除了详细视图中的此视图仅占用屏幕的一半。要做到这一点，我试图通过从细节或toViewController获取最终帧来将此视图设置为最终帧的动画。然而，我得到的框架是来自Interface Builder的toViewController视图的起始框架，而不是AutoLayer在其上传递后出现的视图。如何通过自动布局设置框架后获取框架？我在toViewController特殊视图框架返回animateTransition之前尝试了[self.view layoutSubviews]：但仍然给出了IB布局。

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController* toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    UIViewController* fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    [[transitionContext containerView] addSubview:toViewController.view];
    toViewController.view.alpha = 0;

    [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
        fromViewController.view.alpha = 0;
        toViewController.view.alpha = 1;
        fromViewController.specialView = [toViewController detailSpecialViewFrame];
    } completion:^(BOOL finished) {
        [transitionContext completeTransition:![transitionContext transitionWasCancelled]];

    }];

}

Answer 1

调用layoutIfNeeded而不是layoutSubviews来强制布局传递。然后应该更新框架。

如何在animateTransition期间在ToViewController中获取子视图的框架：？

1 个答案: