容器视图在 completeTransition 上消失: [英] Container view disappearing on completeTransition:

问题描述

我正在使用自定义视图控制器转换，UIViewControllerAnimatedTransitioning，来呈现和关闭视图控制器.

I am using custom view controller transitions, UIViewControllerAnimatedTransitioning, to present and dismiss a view controller.

呈现动画效果很好，但是当我运行关闭动画时，一旦我调用 completeTransition:，containerView 就会被删除.

The presenting animation works fine, but when I run the dismiss animation, once I call completeTransition: the containerView gets removed.

我不确定发生了什么，这是转换代码:

I'm not sure what is going on, here is the transition code:

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

    UIView *containerView = [transitionContext containerView];
    containerView.backgroundColor = [UIColor blackColor];

    if (self.reverse) {
        [containerView addSubview:toViewController.view];
        [containerView addSubview:fromViewController.view];
    } else {
        [containerView addSubview:fromViewController.view];
        [containerView addSubview:toViewController.view];
    }

    if (! self.reverse) { // Forward
        toViewController.view.frame = CGRectMake(-containerView.frame.size.width, 0, containerView.frame.size.width, containerView.frame.size.height);
    } else {
        fromViewController.view.frame = CGRectMake(0, 0, containerView.frame.size.width, containerView.frame.size.height);
    }

    [UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0 usingSpringWithDamping:0.75f initialSpringVelocity:1.0f options:UIViewAnimationOptionCurveLinear animations:^{
        if (self.reverse) {
            fromViewController.view.frame = CGRectMake(-containerView.frame.size.width, 0, containerView.frame.size.width, containerView.frame.size.height);
            fromViewController.view.layer.opacity = 0.f;
            toViewController.view.layer.opacity = 1.f;
        } else {
            toViewController.view.frame = CGRectMake(0, 0, containerView.frame.size.width, containerView.frame.size.height);
            toViewController.view.layer.opacity = 1.f;
            fromViewController.view.layer.opacity = 0.3f;
        }
    } completion:^(BOOL finished) {
        [transitionContext completeTransition:finished];
    }];
}

- (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext {
    if (self.reverse) {
        return 0.45;
    } else {
        return 0.35;
    }
}

如果 .reverse 设置为 YES，如何防止我的 toViewController 消失?

How can I prevent my toViewController from disappearing if .reverse is set to YES?

更新:这是我展示视图控制器的方式:

Update: This is how I'm presenting the view controller:

SecondaryViewController *vc = [[SecondaryViewController alloc] init];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:vc];
navigationController.modalPresentationStyle = UIModalPresentationCustom;
navigationController.transitioningDelegate = self;
[self presentViewController:navigationController animated:YES completion:nil];

推荐答案

容器视图在关闭时消失是正确的行为.您的错误是将 fromView 添加到其中.

The container view disappearing on dismissal is correct behavior. Your mistake is adding the fromView to it.

您错误地区分了这是介绍还是解雇以及在每种情况下您应该做什么.只需使用两个视图控制器 fromViewController 和 toViewController 来区分它们；被解雇时，角色互换.在解雇时，不要向内容视图添加任何内容；原始演示者仍然存在，并将通过容器视图的移除而显示出来.

You are incorrectly distinguishing whether this is presentation or dismissal and what you should do in each case. Simply use the two view controllers fromViewController and toViewController to tell them apart; on dismissal, the roles are reversed. On dismissal, do not add anything to the content view; the original presenter is still present and will be revealed by the removal of the container view.

因此，在演示时，只将 toView 添加到容器视图中.在解雇时，不要向容器视图添加任何内容.就这么简单.

So, on presentation, add only the toView to the container view. On dismissal, do not add anything to the container view. It's as simple as that.

这篇关于容器视图在 completeTransition 上消失: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！