Ios 导航控制器自定义过渡动画

要使用导航控制器(UINavigationController)执行自定义过渡，您应该:

• 定义视图控制器以符合UINavigationControllerDelegate协议.例如，您可以在视图控制器的.m文件中使用私有类扩展来指定与此协议的一致性:

  @interface ViewController () <UINavigationControllerDelegate>
  
  @end
  

• 确保将视图控制器实际指定为导航控制器的代理:

  - (void)viewDidLoad {
      [super viewDidLoad];
  
      self.navigationController.delegate = self;
  }
  

• 在视图控制器中实现animationControllerForOperation:

  - (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
                                    animationControllerForOperation:(UINavigationControllerOperation)operation
                                                 fromViewController:(UIViewController*)fromVC
                                                   toViewController:(UIViewController*)toVC
  {
      if (operation == UINavigationControllerOperationPush)
          return [[PushAnimator alloc] init];
  
      if (operation == UINavigationControllerOperationPop)
          return [[PopAnimator alloc] init];
  
      return nil;
  }
  

• 实现推送和弹出动画的动画师，例如:

  @interface PushAnimator : NSObject <UIViewControllerAnimatedTransitioning>
  
  @end
  
  @interface PopAnimator : NSObject <UIViewControllerAnimatedTransitioning>
  
  @end
  
  @implementation PushAnimator
  
  - (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
  {
      return 0.5;
  }
  
  - (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
  {
      UIViewController* toViewController   = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
  
      [[transitionContext containerView] addSubview:toViewController.view];
  
      toViewController.view.alpha = 0.0;
  
      [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
          toViewController.view.alpha = 1.0;
      } completion:^(BOOL finished) {
          [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
      }];
  }
  
  @end
  
  @implementation PopAnimator
  
  - (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
  {
      return 0.5;
  }
  
  - (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
  {
      UIViewController* toViewController   = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
      UIViewController* fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
  
      [[transitionContext containerView] insertSubview:toViewController.view belowSubview:fromViewController.view];
  
      [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
          fromViewController.view.alpha = 0.0;
      } completion:^(BOOL finished) {
          [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
      }];
  }
  
  @end
  

  这确实会淡入淡出过渡，但您应该可以根据自己的喜好自由自定义动画.

• 如果您想要处理交互手势(例如，类似于从左向右滑动以弹出的本机手势)，您必须实现一个交互控制器:

  • 定义交互控制器(符合UIViewControllerInteractiveTransitioning的对象)的属性:

    @property (nonatomic, strong) UIPercentDrivenInteractiveTransition *interactionController;
    

    这个UIPercentDrivenInteractiveTransition是一个很好的对象，它可以根据手势的完成程度来完成更新自定义动画的繁重任务.

  • 将手势识别器添加到您的视图中.在这里，我只是实现左侧手势识别器来模拟弹出:

    UIScreenEdgePanGestureRecognizer *edge = [[UIScreenEdgePanGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeFromLeftEdge:)];
    edge.edges = UIRectEdgeLeft;
    [view addGestureRecognizer:edge];
    

  • 实现手势识别器处理程序:

    /** Handle swipe from left edge
     *
     * This is the "action" selector that is called when a left screen edge gesture recognizer starts.
     *
     * This will instantiate a UIPercentDrivenInteractiveTransition when the gesture starts,
     * update it as the gesture is "changed", and will finish and release it when the gesture
     * ends.
     *
     * @param   gesture       The screen edge pan gesture recognizer.
     */
    
    - (void)handleSwipeFromLeftEdge:(UIScreenEdgePanGestureRecognizer *)gesture {
        CGPoint translate = [gesture translationInView:gesture.view];
        CGFloat percent   = translate.x / gesture.view.bounds.size.width;
    
        if (gesture.state == UIGestureRecognizerStateBegan) {
            self.interactionController = [[UIPercentDrivenInteractiveTransition alloc] init];
            [self popViewControllerAnimated:TRUE];
        } else if (gesture.state == UIGestureRecognizerStateChanged) {
            [self.interactionController updateInteractiveTransition:percent];
        } else if (gesture.state == UIGestureRecognizerStateEnded) {
            CGPoint velocity = [gesture velocityInView:gesture.view];
            if (percent > 0.5 || velocity.x > 0) {
                [self.interactionController finishInteractiveTransition];
            } else {
                [self.interactionController cancelInteractiveTransition];
            }
            self.interactionController = nil;
        }
    }
    

  • 在导航控制器委托中，您还必须实现interactionControllerForAnimationController个委托方法

    - (id<UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController *)navigationController
                             interactionControllerForAnimationController:(id<UIViewControllerAnimatedTransitioning>)animationController {
        return self.interactionController;
    }
    

如果你在谷歌上搜索"UINavigationController自定义转换教程"，你会得到很多结果.或者看到WWDC 2013 Custom Transitions video.