如何让视图跟随我的手指移动？方向是从左到右

Question

我想实现一个类似于滑块的功能。例如，按钮跟随手指从左向右移动。像这样：

我应该使用 UISwipeGestureRecognizer 吗？还是 UIPanGestureRecognizer？我使用了滑动手势，但我不知道如何更新框架。

var swipeRight = UISwipeGestureRecognizer(target: self, action: 
#selector(self.respondToSwipeGesture(sender:)))
swipeView.isUserInteractionEnabled = true
swipeView.addGestureRecognizer(swipeRight)

Answer 1

如果每次用户手指在屏幕上移动时将他们的手指存储在一个数组中，您就可以做到非常简单。我已经写了一些代码，你可以遵循。它很容易遵循并直接前进。创建一个单一视图应用程序并放置此代码和运行应用程序并查看其结果。

import UIKit

class ViewController: UIViewController {

    let numViewPerRow = 15

    var cells = [String: UIView]()

    override func viewDidLoad() {
        super.viewDidLoad()

        let width = view.frame.width / CGFloat(numViewPerRow)

        let numViewPerColumn = Int(view.frame.height / width)

        for j in 0...numViewPerColumn {
            for i in 0...numViewPerRow {
                let cellView = UIView()
                cellView.backgroundColor = UIColor(red: .random(in: 0...1), green: .random(in: 0...1), blue: .random(in: 0...1), alpha: 1)
                cellView.frame = CGRect(x: CGFloat(i) * width, y: CGFloat(j) * width, width: width, height: width)
                cellView.layer.borderWidth = 0.5
                cellView.layer.borderColor = UIColor.black.cgColor
                view.addSubview(cellView)

                let key = "\(i)|\(j)"
                cells[key] = cellView
            }
        }

        view.addGestureRecognizer(UIPanGestureRecognizer(target: self, action: #selector(handlePan)))
    }

    var selectedCell: UIView?

    @objc func handlePan(gesture: UIPanGestureRecognizer) {
        let location = gesture.location(in: view)

        let width = view.frame.width / CGFloat(numViewPerRow)

        let i = Int(location.x / width)
        let j = Int(location.y / width)
        print(i, j)

        let key = "\(i)|\(j)"

        guard let cellView = cells[key] else { return }

        if selectedCell != cellView {
            UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: .curveEaseOut, animations: {

                self.selectedCell?.layer.transform = CATransform3DIdentity

            }, completion: nil)
        }

        selectedCell = cellView

        view.bringSubviewToFront(cellView)

        UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 1, initialSpringVelocity: 1, options: .curveEaseOut, animations: {

            cellView.layer.transform = CATransform3DMakeScale(3, 3, 3)

        }, completion: nil)

        if gesture.state == .ended {

            UIView.animate(withDuration: 0.5, delay: 0.25, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.5, options: .curveEaseOut, animations: {

                cellView.layer.transform = CATransform3DIdentity

            }, completion: { (_) in

            })
        }
    }
}

Answer 2

您可以将平移手势添加到要拖动的视图。拖动方法如下所示：

func draggedView(_ sender: UIPanGestureRecognizer) {
    let translation = sender.translation(in: self.view)
    draggableView.center = CGPoint(x: draggableView.center.x + translation.x, y: 
    draggableView.center.y)
    sender.setTranslation(CGPoint.zero, in: self.view)
}

您可以使用平移 x 或 y，具体取决于您是要水平移动视图还是垂直移动视图，或者两者都移动。

如何让视图跟随我的手指移动？方向是从左到右

How to make a view follow my finger to move? Direction is from left to right

uiview

uitouch

uigesturerecognizer

ios

swift