iOS开发——自定义转场动画

// 返回负责转场的控制器对象
    func presentationControllerForPresentedViewController(presented: UIViewController, presentingViewController presenting: UIViewController, sourceViewController source: UIViewController) -> UIPresentationController? {
        return PopoverPresentationController(presentedViewController: presented, presentingViewController: presenting)
    }
    
// 返回提供modal动画的对象
    func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        isPresented = true
        return self
    }
    
// 返回提供dismiss动画的对象
    func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        isPresented = false
        return self
    }
    
// 动画时长
    func transitionDuration(transitionContext: UIViewControllerContextTransitioning?) -> NSTimeInterval {
        return 1.2
    }
    
// 转场动画实现函数
    func animateTransition(transitionContext: UIViewControllerContextTransitioning) {
       
     
    }

// 设置转场动画代理
vc.transitioningDelegate = self
// 将转场动画设置为自定义
vc.modalPresentationStyle = UIModalPresentationStyle.Custom