用于以编程方式添加的 UIView 的 UIPanGestureRecognizer

Question

我想在长时间的压力手势后创建圆圈，并在仍然按下屏幕上的手指的同时使其随着平移手势移动。当手指从屏幕上移开时，应从中移除圆圈。使用长按手势创建圆圈效果很好，只是它不会移动。代码如下：

@IBAction func spaceLongPressed(_ guesture: UILongPressGestureRecognizer) {
    let location = guesture.location(in: space)
    var panGesture = UIPanGestureRecognizer()

    circleView = UIView(frame: CGRect(x: location.x - space.bounds.height/4, y: location.y - space.bounds.height/4, width: space.bounds.height/2, height: space.bounds.height/2))

    if guesture.state == .began {

        circleView.backgroundColor = UIColor.red
        circleView.isUserInteractionEnabled = true
        circleView.tag = 100
        circleView.layer.cornerRadius = circleView.bounds.height/2
        space.addSubview(circleView)

        panGesture = UIPanGestureRecognizer(target: space, action: #selector(didPan(sender:)))
        space.addGestureRecognizer(panGesture)
    }

    if guesture.state == .ended {
        if let viewWithTag = self.view.viewWithTag(100) {
            viewWithTag.removeFromSuperview()
        }
    }
}

@objc func didPan(sender: UIPanGestureRecognizer) {

    if sender.state == .began {
    let translation = sender.translation(in: sender.view)

    let changeX = (sender.view?.center.x)! + translation.x
    let changeY = (sender.view?.center.y)! + translation.y

    sender.view?.center = CGPoint(x: changeX, y: changeY)
    sender.setTranslation(CGPoint.zero, in: sender.view)
    }
}

对象 "space" 是 UIButton 类型 - 我想在按钮中创建圆圈。

Answer 1

无需创建panGesture 来更新位置。您可以使用长按手势获得相同的效果。（我对上面的代码做了一点改动，尤其是创建时的视图框架）。

var circleView: UIView!

@IBAction func spaceLongPressed(_ guesture: UILongPressGestureRecognizer) {
    let location = guesture.location(in: view)
    let size = CGSize(width: 100, height: 100)
    circleView = UIView(frame: CGRect(origin: location, size: size))

    if guesture.state == .began {
        circleView.backgroundColor = UIColor.red
        circleView.isUserInteractionEnabled = true
        circleView.tag = 100
        circleView.layer.cornerRadius = circleView.bounds.height/2
        view.addSubview(circleView)
    }

    if guesture.state == .changed {
        let position = guesture.location(in: view)
        if let viewWithTag = self.view.viewWithTag(100) {
            viewWithTag.center = position
        }
    }

    if guesture.state == .ended {
        if let viewWithTag = self.view.viewWithTag(100) {
            viewWithTag.removeFromSuperview()
        }
    }
}

用于以编程方式添加的 UIView 的 UIPanGestureRecognizer

UIPanGestureRecognizer for programmatically added UIView

swift

uipangesturerecognizer

uilongpressgesturerecogni

输出：