iOS:容器视图 - 更改子视图控制器时动画推送过渡

iOS: Container view - animate push transition when changing child view controllers

Apple 在此 document 中讨论了如何在两个子视图控制器之间进行容器视图控制器转换。我想为一个简单的垂直向上滑动设置动画,与 UIModalTransitionStyle 中的 UIModalTransitionStyleCoverVertical 相同。但是,transitionFromViewController 只允许使用 UIViewAnimationOptions,而不是过渡样式。那么如何制作向上滑动视图的动画呢?

奇怪的是,要在子视图控制器之间进行转换,您不能调用类似于 UINavigationController 的简单推送方法来设置转换动画。

加载子视图,在底部屏幕下设置框架origin.y。在动画块中将其更改为 0 后。示例:

enum Animation {
    case LeftToRight
    case RightToLeft
}

func animationForLoad(fromvc: UIViewController, tovc: UIViewController, with animation: Animation) {

        self.addChildViewController(tovc)
        self.container.addSubview(tovc.view)
        self.currentVC = tovc

        var endOriginx: CGFloat = 0

        if animation == Animation.LeftToRight {
            tovc.view.frame.origin.x = -self.view.bounds.width
            endOriginx += fromvc.view.frame.width
        } else {
            tovc.view.frame.origin.x = self.view.bounds.width
            endOriginx -= fromvc.view.frame.width
        }

        self.transition(from: fromvc, to: tovc, duration: 0.35, options: UIViewAnimationOptions.beginFromCurrentState, animations: {
            tovc.view.frame = fromvc.view.frame
            fromvc.view.frame.origin.x = endOriginx
            }, completion: { (finish) in
                tovc.didMove(toParentViewController: self)
                fromvc.view.removeFromSuperview()
                fromvc.removeFromParentViewController()               
        })           
    }

以上代码是 2 个子视图之间的转换,带有推送和弹出水平动画。