调用completeTransition后，在自定义转换中调整导航栏 [英] Navigation bar gets adjusted after calling completeTransition: in custom transition

问题描述

我的目标是为用户提供缩放模式转换，类似于启动应用时的跳板图标放大。

My goal is to provide zooming modal transition from for the user from a view similar as springboard icons zoom in when launching apps.

提供的视图控制器正确放大，但导航栏在状态栏下有错误的位置。此位置在调用[transitionContext completeTransition：finished] ;.如何从转换开始就正确？

The presented view controller zooms in correctly, but the navigation bar has wrong position under the status bar. This position gets corrected after calling [transitionContext completeTransition:finished];. How can I make it correct from the beginning of the transition?

这是一个错误的屏幕录像： http://youtu.be/7LKU4lzb-uw （毛刺位于录音的第6秒）

This is a screen recording of the bug: http://youtu.be/7LKU4lzb-uw (the glitch is in the 6th second of the recording)

UIViewControllerAnimatedTransitioning代码：

The UIViewControllerAnimatedTransitioning code:

- (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];
        }];
}

推荐答案

问题是

切换订单应该可以修复：

Switching the order should fix it:

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

请参阅第4点此处。由于在将导航控制器的视图作为子视图插入之前应用了变换，布局引擎不会认为导航栏位于窗口的顶部边缘，因此不需要调整以避免状态bar。

See point 4 here. Since you've applied a transform prior to inserting the navigation controller's view as a subview, the layout engine doesn't think the navigation bar is at the top edge of the window, and therefore doesn't need to be adjusted to avoid the status bar.

这篇关于调用completeTransition后，在自定义转换中调整导航栏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！