iOS7之定制View Controller切换效果

在iOS5和iOS6前，View Controller的切换主要有4种： 
  • 1. Push/Pop，NavigationViewController常干的事儿
  • 2. Tab，TabViewController点击
  • 3. Present Modal，调用ViewController的presentViewController:animated:completion:方法
  • 4. Add ChildViewController，调用- (void)addChildViewController:(UIViewController *)childController方法


在使用Add ChildViewController的方式时，一般使用transitionFromViewController:toViewController:…的Animation block中可以实现一些简单的切换效果，这样做有2大不足： 
  • 1. 代码高度耦合，VC切换部分的代码直接写在container中，难以分离重用；
  • 2. 支持的切换效果比较有限，因为其只能使用UIView动画来切换，管理起来也略显麻烦


于是，苹果在iOS7中引入了一些新的API来帮助开发者更容易，更松耦合地定义ViewController的转换效果。 

知识点 


用法 
从上面的知识点图中可以看出，新的API主要提供了2种VC切换的方式，一种是动画式切换，即定义一种从一个VC到另一个VC的动画效果，切换的时候自动播放，第二种是交互式切换，这种方式同样需要定义动画效果，只是这个动画效果会根据跟随交互式手势来切换VC并同时播放动画效果。 这两种方式的用法略有不同。 

动画式切换 
  • 首先定义一个动画类实现接口UIViewControllerAnimatedTransitioning， 实现接口的2个方法，一个是动画效果的时间，一个是动画效果（- (void)animateTransition:(id )transitionContext ），实现动画效果时可以从参数transitionContext中获取到切换时的上下文信息，比方说从哪个VC切换到哪个VC等。
  • 在需切换的VC中实现UIViewControllerTransitioningDelegate，并实现animationController*方法，返回一个步骤1定义的动画变量。
  • 调用展现VC切换方法，presentViewController等。


交互式切换 
  • 定义一个类实现接口UIViewControllerInteractiveTransitioning，iOS7提供了一个默认的基于百分比的动画实现UIPercentDrivenInteractiveTransition，大家不想太麻烦可以直接扩展这个类。该类需要绑定需要实现手势控制的VC，同时把手势操作添加到该VC上，然后在处理手势动作的时候，调用接口中的方法去更新当前的动画进度。
  • 定以切换时的动画效果类。和动画式切换的方式一致
  • 在需切换的VC中实现UIViewControllerTransitioningDelegate，实现interactiveController方法，返回步骤1定义的类，实现animationController方法返回步骤2定义的动画效果。


实战 
下图是我实现的一个VC切换的效果图，（注：App图片是网上随便找的，不代表个人喜好：） 
 

实现代码： 
VC跳入动画的代码: 
Object-c代码  收藏代码
  1. -(NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext  
  2. {  
  3.     return 0.5f;  
  4. }  
  5.   
  6. -(void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext  
  7. {  
  8.   
  9.     //Create the differents 3D animations  
  10.     CATransform3D viewFromTransform;  
  11.     CATransform3D viewToTransform;  
  12.       
  13.     UIView *generalContentView = [transitionContext containerView];  
  14.     UIView *fromView = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey].view;  
  15.     UIView *toView = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey].view;  
  16.   
  17.       
  18.     viewFromTransform = CATransform3DMakeRotation(ROTATION_ANGLE, 0.0, 1.0, 0.0);  
  19.     viewToTransform = CATransform3DMakeRotation(-ROTATION_ANGLE, 0.0, 1.0, 0.0);  
  20.     [toView.layer setAnchorPoint:CGPointMake(0, 0.5)];  
  21.     [fromView.layer setAnchorPoint:CGPointMake(1, 0.5)];  
  22.       
  23. //    [generalContentView setTransform:CGAffineTransformMakeTranslation(generalContentView.frame.size.width/2.0, 0)];  
  24.       
  25.     viewFromTransform.m34 = PERSPECTIVE;  
  26.     viewToTransform.m34 = PERSPECTIVE;  
  27.       
  28.     toView.layer.transform = viewToTransform;  
  29.       
  30.   
  31.     //Add the to- view  
  32.     [generalContentView addSubview:toView];  
  33.       
  34.     [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{  
  35.         [generalContentView setTransform:CGAffineTransformMakeTranslation(-generalContentView.frame.size.width/2.0, 0)];  
  36.           
  37.         fromView.layer.transform = viewFromTransform;  
  38.         toView.layer.transform = CATransform3DIdentity;  
  39.           
  40.     } completion:^(BOOL finished) {  
  41.           
  42.         //Set the final position of every elements transformed  
  43.         [generalContentView setTransform:CGAffineTransformIdentity];  
  44.         fromView.layer.transform = CATransform3DIdentity;  
  45.         toView.layer.transform = CATransform3DIdentity;  
  46.         [fromView.layer setAnchorPoint:CGPointMake(0.5f, 0.5f)];  
  47.         [toView.layer setAnchorPoint:CGPointMake(0.5f, 0.5f)];  
  48.           
  49.           
  50.         if ([transitionContext transitionWasCancelled]) {  
  51.             [toView removeFromSuperview];  
  52.         } else {  
  53.             [fromView removeFromSuperview];  
  54.         }  
  55.           
  56.         // inform the context of completion  
  57.         [transitionContext completeTransition:![transitionContext transitionWasCancelled]];  
  58.           
  59.     }];  
  60. }  

手势交互代码： 
Object-c代码  收藏代码
  1. -(void)wireToViewController:(UIViewController *)viewController  
  2. {  
  3.     self.presentingVC = viewController;  
  4.     [self prepareGestureRecognizerInView:viewController.view];  
  5. }  
  6.   
  7. - (void)prepareGestureRecognizerInView:(UIView*)view {  
  8.     UIPanGestureRecognizer *gesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];  
  9.     [view addGestureRecognizer:gesture];  
  10. }  
  11.   
  12. -(CGFloat)completionSpeed  
  13. {  
  14.     return 1 - self.percentComplete;  
  15. }  
  16.   
  17. - (void)handleGesture:(UIPanGestureRecognizer *)gestureRecognizer {  
  18.     CGPoint translation = [gestureRecognizer translationInView:gestureRecognizer.view.superview];  
  19.     switch (gestureRecognizer.state) {  
  20.         case UIGestureRecognizerStateBegan:  
  21.             // 1. Mark the interacting flag. Used when supplying it in delegate.  
  22.             self.interacting = YES;  
  23.             [self.presentingVC dismissViewControllerAnimated:YES completion:nil];  
  24.             break;  
  25.         case UIGestureRecognizerStateChanged: {  
  26.             // 2. Calculate the percentage of guesture  
  27.             CGFloat fraction = -translation.x / 300.0;  
  28.             //Limit it between 0 and 1  
  29.             fraction = fminf(fmaxf(fraction, 0.0), 1.0);  
  30.             self.shouldComplete = (fraction > 0.5);  
  31.               
  32.             [self updateInteractiveTransition:fraction];  
  33.             break;  
  34.         }  
  35.         case UIGestureRecognizerStateEnded:  
  36.         case UIGestureRecognizerStateCancelled: {  
  37.             // 3. Gesture over. Check if the transition should happen or not  
  38.             self.interacting = NO;  
  39.             if (!self.shouldComplete || gestureRecognizer.state == UIGestureRecognizerStateCancelled) {  
  40.                 [self cancelInteractiveTransition];  
  41.             } else {  
  42.                 [self finishInteractiveTransition];  
  43.             }  
  44.             break;  
  45.         }  
  46.         default:  
  47.             break;  
  48.     }  
  49. }  

根据手势3D切换的动画代码： 
Object-c代码  收藏代码
  1. -(NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext  
  2. {  
  3.     return 0.5f;  
  4. }  
  5.   
  6. -(void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext  
  7. {  
  8.   
  9.     //Create the differents 3D animations  
  10.     CATransform3D viewFromTransform;  
  11.     CATransform3D viewToTransform;  
  12.       
  13.     UIView *generalContentView = [transitionContext containerView];  
  14.     UIView *fromView = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey].view;  
  15.     UIView *toView = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey].view;  
  16.   
  17.       
  18.     viewFromTransform = CATransform3DMakeRotation(ROTATION_ANGLE, 0.0, 1.0, 0.0);  
  19.     viewToTransform = CATransform3DMakeRotation(-ROTATION_ANGLE, 0.0, 1.0, 0.0);  
  20.     [toView.layer setAnchorPoint:CGPointMake(0, 0.5)];  
  21.     [fromView.layer setAnchorPoint:CGPointMake(1, 0.5)];  
  22.       
  23. //    [generalContentView setTransform:CGAffineTransformMakeTranslation(generalContentView.frame.size.width/2.0, 0)];  
  24.       
  25.     viewFromTransform.m34 = PERSPECTIVE;  
  26.     viewToTransform.m34 = PERSPECTIVE;  
  27.       
  28.     toView.layer.transform = viewToTransform;  
  29.       
  30.   
  31.     //Add the to- view  
  32.     [generalContentView addSubview:toView];  
  33.       
  34.     [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{  
  35.         [generalContentView setTransform:CGAffineTransformMakeTranslation(-generalContentView.frame.size.width/2.0, 0)];  
  36.           
  37.         fromView.layer.transform = viewFromTransform;  
  38.         toView.layer.transform = CATransform3DIdentity;  
  39.           
  40.     } completion:^(BOOL finished) {  
  41.           
  42.         //Set the final position of every elements transformed  
  43.         [generalContentView setTransform:CGAffineTransformIdentity];  
  44.         fromView.layer.transform = CATransform3DIdentity;  
  45.         toView.layer.transform = CATransform3DIdentity;  
  46.         [fromView.layer setAnchorPoint:CGPointMake(0.5f, 0.5f)];  
  47.         [toView.layer setAnchorPoint:CGPointMake(0.5f, 0.5f)];  
  48.           
  49.           
  50.         if ([transitionContext transitionWasCancelled]) {  
  51.             [toView removeFromSuperview];  
  52.         } else {  
  53.             [fromView removeFromSuperview];  
  54.         }  
  55.           
  56.         // inform the context of completion  
  57.         [transitionContext completeTransition:![transitionContext transitionWasCancelled]];  
  58.           
  59.     }];  
  60. }  


待切换的VC的动画效果配置代码： 
Object-c代码  收藏代码
  1. -(IBAction)changeViewController:(id)sender  
  2. {  
  3.     ToViewController *vc =[[ToViewController alloc] init];  
  4.     vc.delegate = self;  
  5.     vc.transitioningDelegate = self;  
  6.     [self.interactionAnimation wireToViewController:vc];  
  7.     [self presentViewController:vc animated:YES completion:nil];  
  8. }  
  9.   
  10. -(void) didClickedDismissButton:(ToViewController *)viewController  
  11. {  
  12.     [self dismissViewControllerAnimated:YES completion:nil];  
  13. }  
  14.   
  15. - (id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source  
  16. {  
  17.     return self.presentAnimation;  
  18. }  
  19.   
  20. -(id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed  
  21. {  
  22.     return self.cubeAnimation;  
  23. }  
  24.   
  25. -(id <UIViewControllerInteractiveTransitioning>)interactionControllerForDismissal:(id<UIViewControllerAnimatedTransitioning>)animator  
  26. {  
  27.     return self.interactionAnimation.interacting? self.interactionAnimation:nil;  
  28. }  



整个示例的完整代码已提交到Github上：https://github.com/xianlinbox/iOS7_New/tree/master/iOS7_New/VCTransitions
 
posted @ 2016-01-15 13:44  北狐  阅读(122)  评论(0)  编辑  收藏  举报