理论问题:在下面的代码中,为什么在“performSegue ....”的行中,segue不是完全执行的?我的意思是,它是如何知道它是一个交互式过渡,以及为什么方法“performSegue ...”与她在其他地方被宣布的效果不同?
let transitionManager = TransitionManager()
override func viewDidLoad() {
super.viewDidLoad()
transitionManager.sourceViewController = self
// Do any additional setup after loading the view.
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {
let dest = segue.destinationViewController as UIViewController
dest.transitioningDelegate = transitionManager
transitionManager.destViewController = dest
}
segue是从FirstViewController到SecondViewController。
class TransitionManager: UIPercentDrivenInteractiveTransition,UIViewControllerAnimatedTransitioning, UIViewControllerTransitioningDelegate,UIViewControllerInteractiveTransitioning {
var interactive = false
var presenting = false
var panGesture : UIPanGestureRecognizer!
var sourceViewController : UIViewController! {
didSet {
panGesture = UIPanGestureRecognizer(target: self, action: "gestureHandler:")
sourceViewController.view.addGestureRecognizer(panGesture)
}
}
func gestureHandler(pan : UIPanGestureRecognizer) {
let translation = pan.translationInView(pan.view!)
let d = translation.x / pan.view!.bounds.width * 0.5
switch pan.state {
case UIGestureRecognizerState.Began :
interactive = true
sourceViewController.performSegueWithIdentifier("segueIdentifier", sender: self)
case UIGestureRecognizerState.Changed :
self.updateInteractiveTransition(d)
default :
interactive = false
if d > 0.2 || velocity.x > 0 {
self.finishInteractiveTransition()
}
else {
self.cancelInteractiveTransition()
}
}
}
func animateTransition(transitionContext: UIViewControllerContextTransitioning) {
//Something....
UIView.animateWithDuration(1.0, animations: {
//Something....
}, completion: {}
})
}
func transitionDuration(transitionContext: UIViewControllerContextTransitioning) -> NSTimeInterval {
return 1
}
// MARK: UIViewControllerTransitioningDelegate protocol methods
func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
self.presenting = true
return self
}
func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
self.presenting = false
return self
}
func interactionControllerForPresentation(animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
return self.interactive ? self : nil
}
func interactionControllerForDismissal(animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
return self.interactive ? self : nil
}
}
事实上,我有很多与此类似的代码,这个代码正在工作,但其他代码非常相似,正是我所解释的:segue只是在没有交互式转换的情况下执行。有人可以解释一下吗?
谢谢你的帮助
如果问题是您的交互式过渡动画不是交互式的,我建议在interactionControllerForPresentation
中放置一个断点:
interactionControllerForPresentation
实例,就像你认为的那样。
例如,确保目的地的viewDidLoad
没有替换您在源控制器中的transitioningDelegate
中仔细设置的prepareForSegue
...如果从A到B然后再从B到C进行交互式转换,这很容易做到,你预期B到C的设置会干扰你打算从A到B做什么。interactionControllerForPresentation
返回您认为应该的值(即确保interactive
绝对是true
)。每当我看到这种手势的行为没有以交互方式启动过渡时,就像我认为的那样,这是因为当interactionControllerForPresentation
在目标控制器的transitioningDelegate
中被调用时,它没有返回有效的UIViewControllerInteractiveTransitioning
(例如UIPercentDrivenInteractiveTransition
) )就像我想要的那样。
无论如何,你可以通过在interactionControllerForPresentation
中添加一个日志语句来诊断它,你会发现(a)由于某种原因它没有被调用;或(b)self.interactive
不是true
。