自定义UIViewController的转场动画(-)

自定义UIViewController的转场动画

iOS7开始提供了一系列自定义ViewController转场的API

1.UIViewControllerAnimatedTransitioning协议 : 用来自定义一个非交互式的切换动画

```
- (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext;

//定义动画过程
- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext;

```

2.UIViewControllerContextTransitioning 协议：转场动画的上下文

```
- (UIView *)containerView; //用来控制VC切换的容器，将需要push或present进来的view加入改view

//根据key返回对应的Controller key的值：UITransitionContextToViewControllerKey or UITransitionContextFromViewControllerKey
－ (UIViewController *)viewControllerForKey:(NSString *)key; 

- (void)completeTransition:(BOOL)didComplete; 

```

3.UINavigationControllerDelegate ：自定义pop和push动画

```
    //返回自定义的pop或者push动画， 改动画实现了UIViewControllerAnimatedTransitioning
    - (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController 
                              animationControllerForOperation:(UINavigationControllerOperation)operation 
                                           fromViewController:(UIViewController *)fromVC 
                                             toViewController:(UIViewController *)toVC ;

```

4.UIViewCotrollerTransitioningDelegate : 自定义dismiss和present动画

```
-(id<UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source;

-(id<UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed;

```

1. 自定义的动画需要实现UIViewControllerAnimatedTransitioning协议 ，再根据UIViewControllerContextTransitioning协议提供的方法做动画
2. 在firstViewController里实现UIViewCotrollerTransitioningDelegate 或 UIViewCotrollerTransitioningDelegate，在对应的代理方法里返回第一步自定义的动画
   self.navigationController.delegate = self;或者 secondVc.transitioningDelegate = self;