Question

我试图让UIView在滑动触摸的2点之间滑动。我尝试过使用UIPanGestureRecognizer。滑动很好但是当视图到达极限点时，会出现颠簸跳跃。这不顺利。这是我的手势功能：

    func wasDragged(gestureRecognizer: UIPanGestureRecognizer) {
    if gestureRecognizer.state == UIGestureRecognizerState.began || gestureRecognizer.state == UIGestureRecognizerState.changed {
        let translation = gestureRecognizer.translation(in: self.view)
        print(gestureRecognizer.view!.center.x)
        if(gestureRecognizer.view!.center.x <= self.view.frame.width) && (gestureRecognizer.view!.center.x >= self.view.frame.width - 100) {
            gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation.x, y:  gestureRecognizer.view!.center.y)
        }else if (gestureRecognizer.view!.center.x > self.view.frame.width){
            gestureRecognizer.view!.center = CGPoint(x: self.view.frame.width, y: gestureRecognizer.view!.center.y)
        }else if (gestureRecognizer.view!.center.x < self.view.frame.width - 100){
            gestureRecognizer.view!.center = CGPoint(x: self.view.frame.width - 100, y: gestureRecognizer.view!.center.y)
        }

        gestureRecognizer.setTranslation(CGPoint(x: 0,y: 0), in: self.view)
    }


}

有任何帮助吗？感谢。

Answer 1

您的问题是您正在查看视图的位置，而不是应用当前移动后的位置。

我通过引入newx来修复您的代码，@IBAction func wasDragged(gestureRecognizer: UIPanGestureRecognizer) { if gestureRecognizer.state == .began || gestureRecognizer.state == .changed { let translation = gestureRecognizer.translation(in: self.view) print(gestureRecognizer.view!.center.x) let newx = gestureRecognizer.view!.center.x + translation.x if(newx <= self.view.frame.width) && (newx >= self.view.frame.width - 100) { gestureRecognizer.view!.center = CGPoint(x: newx, y: gestureRecognizer.view!.center.y) }else if (newx > self.view.frame.width){ gestureRecognizer.view!.center = CGPoint(x: self.view.frame.width, y: gestureRecognizer.view!.center.y) }else if (newx < self.view.frame.width - 100){ gestureRecognizer.view!.center = CGPoint(x: self.view.frame.width - 100, y: gestureRecognizer.view!.center.y) } gestureRecognizer.setTranslation(CGPoint(x: 0,y: 0), in: self.view) } }显示了视图尝试移动到的位置。这是您想要约束的值。

setTranslation

您可能还想考虑更改最终gestureRecognizer.setTranslation(CGPoint(x: newx - gestureRecognizer.view!.center.x ,y: 0), in: self.view)来电。如果用户尝试在视图已经处于其左边界时向左拖动视图然后（不抬起他们的手指）改变方向并向右移动，则即使他们的手指不再在视图上方，您的代码也会向右移动视图

通过以下更改，在用户的手指返回原始触摸点之前，视图不会向右移动：

environment.yml

试一试，看看你喜欢哪个。

在两个固定点之间滑动UIView

1 个答案: