swift - 在 nslayout 约束上使用 uipangesture

Question

下面我的 swift 代码在 View 加载时使用 nslayout 约束。我尝试在 ImageView 上放置一个 uipangestureRecognizer 。使 ImageView 在 uiview Controller 中移动。现在，如果我触摸 ImageView ，什么也不会发生。我知道我已经对 View 的加载设置了永久约束。我只是不知道如何让 ImageView 移动。我试图移动的 ImageView 是战斗[0]。

  import UIKit

   class ViewController: UIViewController {

var pic = UIImageView()
var draw = UIView()
let fight = (0..<10).map { _ in UIImageView() }
var g2 = UIPanGestureRecognizer()

override func viewDidLoad() {
    super.viewDidLoad()

    fight[0].image  = UIImage(named: "a.png")



    g2 = UIPanGestureRecognizer(target: self, action: #selector(ViewController.g1Method))
    fight[0].addGestureRecognizer(g2)






    fight.forEach{
        $0.backgroundColor = .clear
        view.addSubview($0)
        $0.translatesAutoresizingMaskIntoConstraints = false
    }


    [pic,draw].forEach{
        $0.backgroundColor = .red
        view.addSubview($0)
        $0.translatesAutoresizingMaskIntoConstraints = false

    }
    // Do any additional setup after loading the view.
    NSLayoutConstraint.activate ([




        fight[0].trailingAnchor.constraint(equalTo: view.trailingAnchor, constant :0),
        fight[0].topAnchor.constraint(equalTo: view.topAnchor, constant : 50),

        fight[0].heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.10, constant: 0),
        fight[0].widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.10, constant: 0),
        fight[0].leadingAnchor.constraint(equalTo: view.leadingAnchor, constant : 0),




    ])


}

@objc func g1Method(_ sender: UIPanGestureRecognizer){


    self.view.bringSubviewToFront(sender.view!)
    let tranistioon = sender.translation(in: self.view)
    sender.view!.center = CGPoint(x: sender.view!.center.x + tranistioon.x, y: sender.view!.center.y + tranistioon.y)
    sender.setTranslation(CGPoint.zero,in: self.view)    }




        }

Answer 1

默认情况下，UIImageView不启用用户交互。

在 viewDidLoad() 中添加此行:

fight[0].isUserInteractionEnabled = true

您现在应该能够拖动该 ImageView 。