使用标签组合@objc func 方法

Question

我的代码使用 UIPan gestureRecongnizzer 声明了 2 个不同的 @objc func 方法。我认为会有一种方法可以使用一个标签来使用 1 个 objc func 方法。当前所做的所有功能都是移动图像视图。我不知道标签是否是最好的方式，我对其他解决方案持开放态度，我只想要 1 个功能。具体看pgGestureMethod和sgGestureMethod.

   var pg = UIImageView()
var pgGesture = UIPanGestureRecognizer()
var pgCon = [NSLayoutConstraint]()

var sg = UIImageView()
var sgGesture = UIPanGestureRecognizer()
var sgCon = [NSLayoutConstraint]()

    override func viewDidLoad() {
    super.viewDidLoad()
  [pg,sg].forEach({
        [=10=].translatesAutoresizingMaskIntoConstraints = false
        self.view.addSubview([=10=])
        [=10=].isUserInteractionEnabled = true

    })
    pgGesture = UIPanGestureRecognizer(target: self, action: #selector(ViewController.pgGestureMethod(_:)))
    pg.addGestureRecognizer(pgGesture)


    sgGesture = UIPanGestureRecognizer(target: self, action: #selector(ViewController.sgGestureMethod(_:)))
    sg.addGestureRecognizer(sgGesture)

}

    @objc func pgGestureMethod(_ sender: UIPanGestureRecognizer){

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


}
@objc func sgGestureMethod(_ sender: UIPanGestureRecognizer){

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


}

Answer 1

欢迎使用 Whosebug。

所以在你的情况下，你可以从手势函数中的参数了解调用了哪个手势。

class SomeViewController: UIViewController {
  var pg = UIImageView()
  var pgGesture = UIPanGestureRecognizer()
  var pgCon = [NSLayoutConstraint]()

  var sg = UIImageView()
  var sgGesture = UIPanGestureRecognizer()
  var sgCon = [NSLayoutConstraint]()

  override func viewDidLoad() {
    super.viewDidLoad()

    [pg,sg].forEach {[unowned self] in
      [=10=].translatesAutoresizingMaskIntoConstraints = false
      self.view.addSubview([=10=])
      [=10=].isUserInteractionEnabled = true
    }

    pgGesture = UIPanGestureRecognizer(target: self, action: #selector(gestureDidRecognize(_:)))
    pg.addGestureRecognizer(pgGesture)

    sgGesture = UIPanGestureRecognizer(target: self, action: #selector(gestureDidRecognize(_:)))
    sg.addGestureRecognizer(sgGesture)
  }
}

@objc private extension SomeViewController {
  func gestureDidRecognize(_ gesture: UIPanGestureRecognizer){
    guard let gestureView = gesture.view else { return }

    let transition = gesture.translation(in: view)

    switch gesture {
      case pgGesture:
        view.bringSubviewToFront(pg)

      default: break
    }

    gestureView.center = CGPoint(
      x: gestureView.center.x + transition.x, 
      y: gestureView.center.y + transition.y)

    gesture.setTranslation(.zero, in: view)
  }
}

Answer 2

手势识别器有一个 view 属性来引用它们添加到的视图，所以你甚至不需要标签！

只需使用一个这样的单一操作方法：

@objc func pgGestureMethod(_ sender: UIPanGestureRecognizer){
    // I replaced every "pg" with "sender.view!"
    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)
}

如果不是故意写self.view.bringSubviewToFront(sg)，你可以简单地检查sender.view!:

@objc func pgGestureMethod(_ sender: UIPanGestureRecognizer){
    if sender.view == pg {
        self.view.bringSubviewToFront(pg)
    }
    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)
}

使用标签组合@objc func 方法

use tag to combine @objc func methods

swift

tags

uipangesturerecognizer

func