iOS swift实现转场动画的方法示例

 //需要设置转场动画的控制器titleViewVc.transitioningDelegate = aniamator//这里的animator是animator的实例

class animatorTool: NSObject { lazy var isPresent = false var callBack : ((isPresented:Bool)->())?//向外界传递动画是否正在显示 init(callBack : ((isPresented:Bool)->())) {  self.callBack = callBack }//自定义构造方法，便于给闭包赋值}extension animatorTool:UIViewControllerTransitioningDelegate{ func presentationControllerForPresentedViewController(presented: UIViewController, presentingViewController presenting: UIViewController, sourceViewController source: UIViewController) -> UIPresentationController? {  return AWYPresentationController(presentedViewController: presented, presentingViewController: presenting)//AWYPresentationController是自定义继承自UIPresentationController的类，是为了设置modal出来的vc的view的大小 } func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {  isPresent = true  self.callBack!(isPresented: isPresent)  return self } func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {  isPresent = false  self.callBack!(isPresented: isPresent)  return self }}extension animatorTool:UIViewControllerAnimatedTransitioning{ func transitionDuration(transitionContext: UIViewControllerContextTransitioning?) -> NSTimeInterval {  return 0.5//动画时长 } func animateTransition(transitionContext: UIViewControllerContextTransitioning) {  isPresent ?animatetransitionForPresented(transitionContext) : animatetransitionForDismissed(transitionContext) } func animatetransitionForPresented(transitonContext:UIViewControllerContextTransitioning){  let aimView = transitonContext.viewForKey(UITransitionContextToViewKey)!  transitonContext.containerView()?.addSubview(aimView)  aimView.transform = CGAffineTransformMakeScale(1.0, 0.0)  UIView.animateWithDuration(transitionDuration(transitonContext), animations: {   aimView.layer.anchorPoint = CGPointMake(0.5, 0.0)   aimView.transform = CGAffineTransformIdentity  }) { (_) in   transitonContext.completeTransition(true)  } } func animatetransitionForDismissed(transitonContext:UIViewControllerContextTransitioning){  let aimView = transitonContext.viewForKey(UITransitionContextFromViewKey)!  transitonContext.containerView()?.addSubview(aimView)  UIView.animateWithDuration(transitionDuration(transitonContext), animations: {   aimView.layer.anchorPoint = CGPointMake(0.5, 0.0)   aimView.transform = CGAffineTransformMakeScale(1.0, 0.001)//留一点值，这样会有动画效果  }) { (_) in   transitonContext.completeTransition(true)  } }}