提交前的快速segue自定义过渡布局

Question

I have two view controllers, A and B. I can go from A to B via a segue and I have implemented a fade in animation on the segue by implementing a UISegue class. However, problems occur during rotation of the device and the unwind (from B to A, while rotation has occurred whilst in B).

The problem that occurs is that the view to present (view A) has a wrong layout. Calling functions like setNeedsUpdateConstraints() or layoutSubviews() or similar functions before the transitions aren't working. The screenshot describes the situation where A is opened in landscape and then the segue to B is performed. When in B, the device is rotated back to portrait and unwound to A.

The Swift code for the segues:

class SegueFadeOut: UIStoryboardSegue {

    override func perform() {
        UIView.transition(from: source.view, to: destination.view, duration: 5.5, options: [.transitionCrossDissolve]) { (success) in
            self.destination.dismiss(animated: false, completion: nil)
        }
    }

}

class SegueFadeIn: UIStoryboardSegue {

    override func perform() {
        let toViewController = self.destination
        let fromViewController = self.source

        let containerView = fromViewController.view.superview

        toViewController.view.alpha = 0.0
        containerView?.addSubview(toViewController.view)

        UIView.animate(withDuration: 0.5, delay: 0, options: .curveEaseInOut, animations: {
            toViewController.view.alpha = 1.0
        }, completion: { success in
            fromViewController.present(toViewController, animated: false, completion: nil)
        })
    }

}

Any clues on how or where to implement a function that will fix this layout problem? Thanks!

Answer 1

I have managed to fix it. I can set the frame right before executing the animation. I also stopped using the UIView.transition(...) function, as it gave some errors during the dismissal of the fromViewController.

class SegueFadeOut: UIStoryboardSegue {

    override func perform() {
        let toViewController = self.destination
        let fromViewController = self.source

        let containerView = fromViewController.view.superview

        toViewController.view.alpha = 0.0
        // ADDED LINE BELOW
        toViewController.view.frame = fromViewController.view.frame

        containerView?.addSubview(toViewController.view)

        UIView.animate(withDuration: 0.5, delay: 0, options: .curveEaseInOut, animations: {
            toViewController.view.alpha = 1.0
        }, completion: { success in
            fromViewController.dismiss(animated: false, completion: nil)
        })
    }

}