自定义转换动画不会在关闭时调用VC生命周期方法 [英] Custom transition animation not calling VC lifecycle methods on dismiss

问题描述

所以我构建了一个自定义呈现过渡动画，除了视图控制器生命周期方法没有被调用时，一切看起来都很好。

So I built a custom presenting transition animation and everything seems to be working great except the view controller lifecycle methods are not being called on dismiss.

在呈现控制器之前，我使用 UIModalPresentationCustom 样式将呈现VC保留在视图层次结构中，但是一旦我关闭呈现的VC，viewWillAppear和viewDidAppear不会在我的呈现控制器上调用。我错过了一个我需要明确调用以获取这些方法的步骤吗？我知道手动调用这些方法不是正确的解决方案。

Before presenting the controller I use the UIModalPresentationCustom style to keep the presenting VC in the view hierarchy, but once I dismiss the presented VC, viewWillAppear and viewDidAppear are not called on my presenting controller. Am I missing a step that I need to explicitly call to get those methods to fire? I know manually calling those methods is not the correct solution.

这是我的解雇动画代码。我基本上是动画表单覆盖视图，以便在解雇时缩小到集合视图单元格的大小。

Here is my dismissing animation code. I'm basically animating a form overlay view to shrink to the size of a collection view cell on dismissal.

- (void)_animateDismissingTransitionWithContext:(id<UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

    UICollectionView *destinationCollectionView = toCollectionViewController.collectionView;
    UICollectionViewCell *destinationCollectionViewCell = [self _destinationCellFromContext:transitionContext];
    UIView *containerView = transitionContext.containerView;

    // Calculate frames    
    CGRect startFrame = fromEventDetailViewController.detailContainerView.frame;
    CGRect endFrame = [destinationCollectionView convertRect:destinationCollectionViewCell.frame toView:containerView];

    // Add overlay
    UIView *overlayView = [UIView new];
    overlayView.backgroundColor = [UIColor overlayBackground];
    overlayView.frame = containerView.bounds;
    overlayView.alpha = 1.0f;
    [containerView addSubview:overlayView];

    // Add fake detail container view
    UIView *fakeContainerView = [UIView new];
    fakeContainerView.backgroundColor = fromEventDetailViewController.detailContainerView.backgroundColor;
    fakeContainerView.frame = startFrame;
    [containerView addSubview:fakeContainerView];

    // Hide from view controller
    fromEventDetailViewController.view.alpha = 0.0f;

    [UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0.0f usingSpringWithDamping:0.75f initialSpringVelocity:0.2f options:UIViewAnimationOptionCurveEaseOut animations:^{
        fakeContainerView.frame = endFrame;
        fakeContainerView.backgroundColor = [UIColor eventCellBackground];

        overlayView.alpha = 0.0f;
    } completion:^(BOOL finished) {
        [fromEventDetailViewController.view removeFromSuperview];
        [overlayView removeFromSuperview];
        [fakeContainerView removeFromSuperview];

        [transitionContext completeTransition:YES];
    }];
}

推荐答案

另一种解决方案可能是使用 beginAppearanceTransition：和 endAppearanceTransition：。根据文档：

Another solution could be using beginAppearanceTransition: and endAppearanceTransition:. According to documentation:

如果要实现自定义容器控制器，请使用此方法
告诉孩子其视图是即将出现或消失。
不会调用viewWillAppear：，viewWillDisappear：，viewDidAppear：或
viewDidDisappear：直接。

If you are implementing a custom container controller, use this method to tell the child that its views are about to appear or disappear. Do not invoke viewWillAppear:, viewWillDisappear:, viewDidAppear:, or viewDidDisappear: directly.

这是我如何使用它们：

- (void)animationEnded:(BOOL)transitionCompleted
{
    if (!transitionCompleted)
    {
        _toViewController.view.transform = CGAffineTransformIdentity;
    }
    else
    {
        [_toViewController endAppearanceTransition];
    }
}

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

    [toViewController beginAppearanceTransition:YES animated:YES];
    // ... other code
}

但我还是觉得奇怪那个自定义模态演示没有这样做。

But I still consider strange that custom modal presentation not doing this.

这篇关于自定义转换动画不会在关闭时调用VC生命周期方法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！