如何使用xib文件设置UIPanGestureRecognizer

Question

func handlePanGesture (panGesture: UIPanGestureRecognizer) {
            let translation = panGesture.translation(in: panGesture.view?.superview)
            if panGesture.state == .began || panGesture.state == .changed {
                panGesture.view?.center = CGPoint(x: (panGesture.view?.center.x)! + translation.x, y: (panGesture.view?.center.y)! + translation.y)

                let distance: Double = sqrt(pow((Double(panGesture.view!.center.x) - Double(poin1.x)),2) + pow((Double(panGesture.view!.center.y) - Double(poin1.y)),2))
                if distance <= 50{
                    panGesture.view!.center.x = CGFloat(poin1.x)
                    panGesture.view!.center.y = CGFloat(poin1.y)

                }
                panGesture.setTranslation(CGPoint.zero, in: self.view)
            }
        }

我希望自定义func handlePanGesture使用许多点来移动手势。