ios - 动画并不总是从 UIViewControllerAnimatedTransitioning 中的 animateTransition 可见

Question

我正在使用一些 UIViewController包含在 UINavigationController 中.

一个人会收到一个推送 segue来自UIButton在 storyboard 上, 然后使用调用的滑动手势将其关闭

popViewControllerAnimated

我正在使用 UINavigationControllerDelegate提供符合 UINavigationControllerDelegate 的自定义对象. animateTransition 的代码如下所示。

我的问题是，第一次运行时， View 会在呈现时显示动画，但之后每次都不会显示动画(它只是立即出现)。

有人能帮忙吗？

谢谢!

-(void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext {

//Get references to the view hierarchy
UIView *containerView = [transitionContext containerView];
UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];


if (self.isPresenting) {

    [containerView insertSubview:toViewController.view belowSubview:fromViewController.view];

    [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
        fromViewController.view.transform = CGAffineTransformMakeTranslation(-1000, 0);
    } completion:^(BOOL finished) {
        [transitionContext completeTransition:YES];
    }];

} else if (!self.isPresenting) {
    //Add 'to' view to the hierarchy
    [containerView insertSubview:toViewController.view belowSubview:fromViewController.view];

    //Scale the 'from' view down until it disappears
    [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
        //toViewController.view.transform = CGAffineTransformMakeScale(1.0, 1.0);
        fromViewController.view.transform = CGAffineTransformMakeScale(0.01, 0.01);
    } completion:^(BOOL finished) {
        [transitionContext completeTransition:YES];
    }];
}
}

Answer 1

升级到 iOS8 后，我遇到了一组类似的问题。需要检查的几件事:

1. 确保在开始动画之前调用这些:

   [toViewController beginAppearanceTransition:YES animated:YES];
[fromViewController beginAppearanceTransition:NO animated:YES];

2. 然后在完成 block 中调用这些:

   [toViewController endAppearanceTransition]；
[fromViewController endAppearanceTransition];
[transitionContext completeTransition:finished];

需要以上内容来确保在正确的时间调用 viewWillAppear: 和 viewWillDisappear:。

1. 设置 modalPresentationStyle = UIModalPresentationFullScreen，而不是 UIModalPresentationCustom(其行为非常不同)。

希望这对您有所帮助。

干杯!