How do I cross dissolve when pushing views on a UINavigationController in iOS 7?

Question

If I simply call the push method with:

[self.navigationController pushViewController:viewController animated:YES];

then it uses a push animation. How do I change it to use a cross dissolve animation, like I can with a modal segue?

Answer 1

You can use a CATransition as demonstrated in this answer:

CATransition* transition = [CATransition animation];
transition.duration = 0.5;
transition.type = kCATransitionFade;
[self.navigationController.view.layer addAnimation:transition forKey:nil];
[self.navigationController pushViewController:viewController animated:NO];

Answer 2

I use an extension for easy reuse:

extension UINavigationController {
    func fadeTo(_ viewController: UIViewController) {
        let transition: CATransition = CATransition()
        transition.duration = 0.3
        transition.type = kCATransitionFade
        view.layer.add(transition, forKey: nil)
        pushViewController(viewController, animated: false)
    }
}

Notice how animated is false; when you set it to true, you still see the standard 'push' animation (right to left).

Answer 3

The UINavigationControllerDelegate protocol has a method that can return a custom UIViewControllerAnimatedTransitioning object which will control the animation between the two view controllers involved in the transition.

Create an Animator class to control the cross-dissolve transition:

class Animator: NSObject, UIViewControllerAnimatedTransitioning {
    
    let animationDuration = 0.25
    
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return animationDuration
    }
    
    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        let toVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)
        toVC?.view.alpha = 0.0
        let fromVC = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)
        transitionContext.containerView.addSubview(fromVC!.view)
        transitionContext.containerView.addSubview(toVC!.view)
    
        UIView.animate(withDuration: animationDuration, animations: {
            toVC?.view.alpha = 1.0
        }) { (completed) in
            fromVC?.view.removeFromSuperview()
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        }
    }
}

And provide it in your UINavigationControllerDelegate:

func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return Animator()
}

Here is a more in-depth tutorial: https://web.archive.org/web/20191204115047/http://blog.rinatkhanov.me/ios/transitions.html

Answer 4

SWIFT 3, 4.2 -- as of October, 2019

let transition = CATransition()
transition.duration = 0.5
transition.type = kCATransitionFade
self.navigationController?.view.layer.add(transition, forKey:nil)

Answer 5

You can set Push viewcontroller like this.

        CATransition* transition = [CATransition animation];
        transition.duration = 0.4;
        transition.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
        transition.type = kCATransitionFade;
        [self.navigationController.view.layer addAnimation:transition forKey:@"kCATransition"];
        [self.navigationController pushViewController:readerViewController animated:false];

You can set Pop viewcontroller like this.

         CATransition* transition = [CATransition animation];
         transition.duration = 0.4;
         transition.timingFunction = [CAMediaTimingFunction 
         functionWithName:kCAMediaTimingFunctionEaseOut];
         transition.type = kCATransitionFade;
         [self.navigationController.view.layer addAnimation:transition 
          forKey:@"kCATransition"];
         [self.navigationController popViewControllerAnimated:false];

Answer 6

Update Swift 5

Using prepare(for segue:) instead of pushViewController:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    // other preparations

    let transition: CATransition = CATransition()
    transition.duration = 0.3
    transition.type = CATransitionType.fade
    navigationController?.view.layer.add(transition, forKey: nil)
}