Kuidas saab rakendada oma animatsioonilise ülemineku Navigation Controlleris ekraanide vahel?

Selleks, et rakendada oma animatsioonipõhist üleminekut ekraanide vahel UINavigationControlleris, peate kasutama protokolle UIViewControllerAnimatedTransitioning ja UINavigationControllerDelegate.

1. Looge klass, mis implementeerib UIViewControllerAnimatedTransitioning, kus kirjeldate animatsiooni loogikat:

   • transitionDuration(using:) — animatsiooni kestus
   • animateTransition(using:) — ise ülemineku animatsioon

2. Määrake UINavigationControlleri delegaadiks objekt, mis implementeerib UINavigationControllerDelegate, ja meetodis:

   func navigationController(_ navigationController: UINavigationController, 
                             animationControllerFor operation: UINavigationController.Operation, 
                             from fromVC: UIViewController, 
                             to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
       // tagastate oma animatsiooni objekti
       return customAnimator
   }
   

Näide lihtsast kohandatud animatorist:

class CustomAnimator: NSObject, UIViewControllerAnimatedTransitioning {
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.3
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        guard let toView = transitionContext.view(forKey: .to) else {
            transitionContext.completeTransition(false)
            return
        }
        let container = transitionContext.containerView
        toView.alpha = 0
        container.addSubview(toView)

        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
            toView.alpha = 1
        }) { finished in
            transitionContext.completeTransition(finished)
        }
    }
}