如何在UINavigationController中使用UIViewControllerAnimatedTransitioning？

Question

How can I get custom transitions (iOS7) when pushing a view controller onto UINavigationController ? I tried setting the TransitioningDelegate both in the UINavigationController and also on the controller I'm pushing The methods never get called.

All examples I find use custom transitions when presenting modally.

Answer 1

@rounak has the right idea, but sometimes it helps to have code ready without having to download from github.

Here are the steps that I took:

1. Make your FromViewController.m conform to UINavigationControllerDelegate . Other sample code out there tells you to conform to UIViewControllerTransitioningDelegate , but that's only if you're presenting the ToViewController.

   @interface ViewController : UIViewController

2. Return your custom transition animator object in the delegate callback method in FromViewController:

    - (id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC { TransitionAnimator *animator = [TransitionAnimator new]; animator.presenting = (operation == UINavigationControllerOperationPush); return animator; } 

3. Create your custom animator class and paste these sample methods:

    - (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext { return 0.5f; } - (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext { // Grab the from and to view controllers from the context UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey]; UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey]; // Set our ending frame. We'll modify this later if we have to CGRect endFrame = CGRectMake(80, 280, 160, 100); if (self.presenting) { fromViewController.view.userInteractionEnabled = NO; [transitionContext.containerView addSubview:fromViewController.view]; [transitionContext.containerView addSubview:toViewController.view]; CGRect startFrame = endFrame; startFrame.origin.x += 320; toViewController.view.frame = startFrame; [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{ fromViewController.view.tintAdjustmentMode = UIViewTintAdjustmentModeDimmed; toViewController.view.frame = endFrame; } completion:^(BOOL finished) { [transitionContext completeTransition:YES]; }]; } else { toViewController.view.userInteractionEnabled = YES; [transitionContext.containerView addSubview:toViewController.view]; [transitionContext.containerView addSubview:fromViewController.view]; endFrame.origin.x += 320; [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{ toViewController.view.tintAdjustmentMode = UIViewTintAdjustmentModeAutomatic; fromViewController.view.frame = endFrame; } completion:^(BOOL finished) { [transitionContext completeTransition:YES]; }]; } } 

Essentially, the animator is the object doing the heavy lifting. Of course, you can make your UINavigationControllerDelegate be a separate object, but that depends on how your architect your app.

Answer 2

objc.io's post on view controller transitions are specifically for pushing and popping view controllers. http://objc.io/issue-5/view-controller-transitions.html

I've done this animation ( http://i.imgur.com/1qEyMu3.gif ) solely based on the objc.io post.

In short you have to have a class(es) implementing UINavigationControllerDelegate , and UIViewControllerAnimatedTransitioning with the required methods for returning the correct animator, and performing the animations.

Answer 3

You can look at my demo project which demonstrates using custom transitions in UINavigationController . Look at https://github.com/Vaberer/BlurTransition .

Answer 4

EDIT: Just realised this might not answer your question. But it is an alternative.

If you're using a storyboard you can do a custom transition by creating a custom segue. In the attributes inspector change the segue class name to your custom transition class eg MySegue . Then create the MySegue class and implement the -(void)perform method to perform your transition.

- (void) perform{
      UIViewController *source = self.sourceViewController;
      UIViewController *destination = self.destinationViewController;
      [UIView transitionFromView:source.view
                          toView:destination.view
                        duration:0.50f
                         options:UIViewAnimationOptionTransitionFlipFromTop
                      completion:nil];
}