ios - 如何在 UINavigationController 中使用 UIViewControllerAnimatedTransitioning？

Question

将 View Controller 推送到 UINavigationController 时如何获得自定义转换 (iOS7)？我尝试在 UINavigationController 和我正在推送的 Controller 上设置 TransitioningDelegate这些方法永远不会被调用。

我发现的所有示例在模态呈现时都使用自定义过渡。

Answer 1

@rounak 的想法是正确的，但有时无需从 github 下载就可以准备好代码。

以下是我采取的步骤:

1. 使您的 FromViewController.m 符合 UINavigationControllerDelegate。其他示例代码告诉您遵守 UIViewControllerTransitioningDelegate，但这只是在您呈现 ToViewController 的情况下。

   @interface ViewController : UIViewController

2. 在 FromViewController 的委托(delegate)回调方法中返回您的自定义过渡动画对象:

   - (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. 创建您的自定义动画师类并粘贴这些示例方法:

   - (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];
       }];
   }
   }
   

从本质上讲，动画师是承担繁重工作的对象。当然，您可以让您的 UINavigationControllerDelegate 成为一个单独的对象，但这取决于您的应用架构师的方式。