1. 首先被push的VC要签订 <UINavigationControllerDelegate>
2.实现协议方法- (nullable id <UINavigationControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC
{
//在这里返回一个UINavigationControllerAnimatedTransitioning的实例
NSObject<UINavigationControllerAnimatedTransitioning>animated;
animated = [Animator alloc] init];
return animated;
}
3.实现Animator类
3.1 首先Animator 遵循代理方法<UINavigationControllerAnimatedTransitioning>
3.2 实现代理方法
3.2.1 - (NSTimeInterval)transitionDuration:
(id<UINavigationControllerAnimatedTransitioning>)transitionContext
{
//动画时间
return ANIMATION_TIME;
}
3.2.2 - (void)animationTransition:
(id<UINavigationControllerAnimatedTransitioning>)transitionContext
{
//transitionContext 上下文
UIView *container = [transitionContext containerView];
//获取当前VC
UIViewController *fromVC = [transitionContext
viewControllerForKey:UITransitionContextFromViewControllerKey];
//获取要pop到的VC
UIViewController *toVC = [transitionContext
viewControllerForKey:UITransitionContextToViewControllerKey];
//自己实现的转场动画.............
//结束完成转场
[transitionContext completeTransition:YES];
}
//常用到的方法
//7.0后的新方法，截取一段自定义大小的当前屏幕显示的VIEW ，可设置偏移量。 afterUpdates(个人理解：参数如果为NO，直接截取当前选中VIEW，如果为YES，会等当前选中的VIEW刷新到最新状态时候在更新)
- (UIView *)resizableSnapshotViewFromRect:(CGRect )rect afterScreenUpdates:(BOOL)afterUpdates withCapInsets:(UIEdgeInsets)capInsets; NS_AVAILABLE_IOS(7_0)
