UIView幻灯片动画从左到右有问题吗？

Question

我试图动画2个UIViews ，UIView1存在，并在一个按钮水龙头，UIView2由右至左滑动并占据屏幕，移动UIView1闪开。

那部分我可以使用slideLeftTransitionFromView成功实现。 但是，再次单击按钮以使用slideRightTransitionFromView从左向右滑动slideRightTransitionFromView ，UIView1在动画过程中会以某种方式消失。 UIView2确实可以成功地从左向右滑动，但是我看不到UIView1。

我敢肯定， slideRightTransitionFromView遵循类似的逻辑作为slideLeftTransitionFromView ，但我无法得到它的工作。

这是两个功能：

func slideLeftTransitionFromView(view: UIView, toView: UIView, duration: NSTimeInterval, completion: ((Bool) -> Void)?)
{
    if let container = view.superview
    {
        // Final position of outgoing view
        let outgoingViewEndX = view.frame.origin.x - view.frame.size.width

        // Final position of incoming view (existing frame)
        let incomingViewEndX = view.frame.origin.x

        // Start point of incoming view -- at the right edge of the outgoing view
        let incomingViewStartX = view.frame.origin.x + view.frame.size.width

        // Distance traveled by outgoing view
        let outgoingDisplacement = view.frame.origin.x - outgoingViewEndX

        toView.frame.origin = CGPointMake(incomingViewStartX, toView.frame.origin.y)
        container.addSubview(toView)

        dispatch_async(dispatch_get_main_queue(), { ()
            UIView.animateWithDuration(duration, delay: 0, options: .CurveLinear, animations: {

                view.frame.origin.x = outgoingViewEndX
                toView.frame.origin.x = incomingViewEndX

                }, completion: {(complete: Bool) in

                    // If the outgoing view is still in onscreen, keep sliding until it's offscreen
                    if outgoingViewEndX + view.frame.size.width > 0 {

                        // Adjust the duration for the final animation based on the distance it has to travel in order to keep the same velocity.
                        let finalDuration = duration * Double((outgoingViewEndX + view.frame.size.width)/outgoingDisplacement)

                        UIView.animateWithDuration(finalDuration, delay: 0, options: .CurveLinear, animations: {

                            view.frame.origin.x = -view.frame.size.width
                            }, completion: { (complete: Bool) in
                                completion?(complete)
                                view.removeFromSuperview()
                        })
                    }
                    else
                    {
                        completion?(complete)
                        view.removeFromSuperview()
                    }
            })
        })
    }
}

func slideRightTransitionFromView(view: UIView, toView: UIView, duration: NSTimeInterval, completion: ((Bool) -> Void)?)
{
    if let container = view.superview
    {
        // Final position of outgoing view
        let outgoingViewEndX = view.frame.origin.x + view.frame.size.width

        // Final position of incoming view (existing frame)
        let incomingViewEndX = view.frame.origin.x

        // Start point of incoming view -- at the left edge of the outgoing view
        let incomingViewStartX = view.frame.origin.x - view.frame.size.width

        // Distance traveled by outgoing view
        let outgoingDisplacement = view.frame.origin.x + outgoingViewEndX

        toView.frame.origin = CGPointMake(incomingViewStartX, toView.frame.origin.y)
        container.addSubview(toView)

        dispatch_async(dispatch_get_main_queue(), { ()
            UIView.animateWithDuration(duration, delay: 0, options: .CurveLinear, animations: {

                view.frame.origin.x = outgoingViewEndX
                toView.frame.origin.x = incomingViewEndX

                }, completion: {(complete: Bool) in

                    // If the outgoing view is still in onscreen, keep sliding until it's offscreen
                    if outgoingViewEndX + view.frame.size.width < 0 {

                        // Adjust the duration for the final animation based on the distance it has to travel in order to keep the same velocity.
                        let finalDuration = duration * Double((outgoingViewEndX + view.frame.size.width)/outgoingDisplacement)

                        UIView.animateWithDuration(finalDuration, delay: 0, options: .CurveLinear, animations: {

                            view.frame.origin.x = view.frame.size.width
                            }, completion: { (complete: Bool) in
                                completion?(complete)
                                view.removeFromSuperview()
                        })
                    }
                    else
                    {
                        completion?(complete)
                        view.removeFromSuperview()
                    }
            })
        })
    }
}

这可能很简单，但我看不到。 似乎是什么问题？

谢谢

Answer 1

您可能已将UIView IBOutlet声明为弱变量

在slideLeftTransitionFromView调用view.removeFromSuperview()从视图层次结构中删除该视图，并且可以确定您的视图已被释放，因为它是一个弱var，不再是布局的一部分。

因此，稍后尝试再次将其添加为子视图时，您看不到它。 尝试使var成为强参考。