可拖动的UIView不能平稳移动，只能拖动一小段距离（包括视频）

Question

视频：https://www.youtube.com/watch?v=8_xCTJAld9Y&feature=youtu.be。在这里您可以看到我的问题，但我不知道到底是哪里错了。我无法随意移动它。

我有一个可拖动的UIView，它具有一个自定义类：

import UIKit

class UIViewDraggable: UIView {

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    self.isUserInteractionEnabled = true
}


override init(frame: CGRect) {
    super.init(frame: frame)

}


override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    let touch = touches.first;
    let location = touch?.location(in: self.superview);
    if(location != nil)
    {
    self.frame.origin = CGPoint(x: location!.x-self.frame.size.width/2, y: location!.y-self.frame.size.height/2);
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

    }
}

我通过点击按钮创建UIView：

import UIKit

class UIViewDraggable: UIView {

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
    self.isUserInteractionEnabled = true
}


override init(frame: CGRect) {
    super.init(frame: frame)

}


override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    let touch = touches.first;
    let location = touch?.location(in: self.superview);
    if(location != nil)
    {
    self.frame.origin = CGPoint(x: location!.x-self.frame.size.width/2, y: location!.y-self.frame.size.height/2);
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

    }
}

如何实现完全平滑的可拖动UIView？

Answer 1

向视图添加panGesture，然后根据触摸位置更新view.center

let pan = UIPanGestureRecognizer(target: self, action: #selector(panView))
self.addGestureRecognizer(pan)

然后将其用作：

@objc func panView(pan: UIPanGestureRecognizer) {

    let location = pan.location(in: self.superView) // get pan location

    switch pan.state {
    case .began:
        print("began")
    case .changed:
        self.center = location
        // updated your frames here
    default:
        print("nothing")
    }
 }