Question

我有UIView（图像中的红色）我可以在x轴上平移。我可以将视图恢复到原始位置，但我想回到那个位置，好像它被一个轻弹簧拉动，或者某种缓慢回到原始位置。

此刻它奇怪地跳回到那个位置。

这是我的相关代码，附上图片以显示其中的最大位置。

@IBAction func handlePan(recognizer:UIPanGestureRecognizer) {

        if recognizer.state == UIGestureRecognizerState.Ended {

            print(backgroundView.center.x) //120.0
            print(backgroundView.center.y) //64.0

            let xDivision = Double(backgroundView.center.x/120.0)
            print(xDivision)

            recognizer.view?.center = CGPointMake(120.0, 64.0)

            self.view.frame = CGRectMake(backgroundView.center.x, 0, self.view.frame.width , self.view.frame.height)

            UIView.animateWithDuration(xDivision, delay: 0.0, usingSpringWithDamping: 2.0, initialSpringVelocity: 2.0, options: UIViewAnimationOptions.CurveEaseIn, animations: {

                self.view.center.x = 120.0

                }, completion: { (true) in

                    print("Animation Complete")
                    print(self.backgroundView.center.x)
            })



        }

        let translation: CGPoint = recognizer.translationInView(self.view)
        //recognizer.view?.center = CGPointMake((recognizer.view?.center.x)!, (recognizer.view?.center.y)! + translation.y)
        recognizer.setTranslation(CGPointMake(0, 0), inView: self.view)


        var center: CGPoint = (recognizer.view?.center)!
        print(center.x)
        center.x += translation.x
        if center.x < 50.0 || center.x > 320.0 {
            return
        }
        recognizer.view?.center = center

    }

关于如何实现这一目标的任何想法。这个动画就是一个很好的例子 - http://rise.simplebots.co

感谢。

Answer 1

如果使用自动布局，更改框架或中心属性可能会导致问题。你有没有考虑过改变约束的常数？像：

@IBAction func handlePan(recognizer:UIPanGestureRecognizer) {

    switch recognizer.state {
    case .Began:
        //do something

    case .Changed:
        let translation = recognizer.translationInView(self.view)
        self.leftContraint.constant = self.leftContraint.constant + translation.x
        recognizer.setTranslation(.zero, inView: self.view)

    case .Ended:
        UIView.animateWithDuration(1,
            delay: 0,
            options: .CurveEaseOut,
            animations: {
                self.leftContraint.constant = //your value
                self.view.layoutIfNeeded()
            },
            completion: nil)

    default: ()
    }
}

这帮助我解决了类似的问题。

平移手势后，将视图返回到原始位置，快速

1 个答案: