Swift：Tap Gesture Recognizer并非每次都起作用

Question

我有一个奇怪的问题。我在子视图中添加了一个基本的轻击手势识别器，但仅在喜欢时才起作用。有时，它可以在第二次点击时起作用，有时在第三次甚至更多次点击时起作用。但是，当我向手势识别器调用的函数添加print("whatever")时，该函数始终在我第一次单击该子视图时起作用。

我该如何解决？

在这两个示例上出现相同的问题：

SubView：

let getGiftGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.getGift))
self.continueButton.addGestureRecognizer(getGiftGestureRecognizer)

        DispatchQueue.main.async {
            self.coverAnyUIElement(element: self.successView)
            let gift = SCNNode()
             gift.geometry = SCNBox(width: 1, height: 1, length: 1, chamferRadius: 0)

             //nahodne vygenerovat geometry, nebo barvu
             let ownedGeometries = UserDefaults.standard.array(forKey: "ownedGeometries")
             let ownedColors = UserDefaults.standard.array(forKey: "ownedColors")
             let notOwnedGeometriesCount = geometriesCount - ownedGeometries!.count
             let notOwnedColorsCount = colorsCount - ownedColors!.count

             if notOwnedGeometriesCount == 0{
                 //mam vsechny geometrie
                 //vygeneruju barvu

             }else if notOwnedColorsCount == 0{
                 //mam vsechny barvy
                 //vygeneruju geometrii
             }else if(notOwnedGeometriesCount == 0 && notOwnedColorsCount == 0){
                 //mam uplne vsechno

             }else{
                 //vygeneruj cokoliv
                 let random = Int.random(in: 0...10)
                 if random <= 3{

                     //vygeneruj geometrii
                 }else{
                     //vygeneruj barvu
                 }
             }
             print(self.generateColor())
             print(self.generateGeometry())



            self.chest.opacity = 1
             self.chest.position.y = -1.8
             self.world.addChildNode(self.chest)
             let viko = self.chest.childNode(withName: "viko", recursively: false)
             self.chest.addChildNode(gift)

            print("VLAKNO1: \(Thread.isMainThread)")
             viko?.runAction(SCNAction.rotateBy(x: 0, y: 0, z: -90/(180/CGFloat.pi), duration: 1),completionHandler: {
                print("VLAKNO2: \(Thread.isMainThread)")

                    let pohyb = SCNAction.move(by: SCNVector3(0,4,0), duration: 1)
                    gift.runAction(pohyb,completionHandler: {
                       print("VLAKNO3: \(Thread.isMainThread)")

                            self.showConfirmGiftButton()


                    })


             })
        }
    }

按钮：

confirmGiftButton.addTarget(self, action: #selector(acceptedGift), for: .touchUpInside)

@objc func acceptedGift(){
        DispatchQueue.main.async {
            UIButton.animate(withDuration: 0.2, animations: {
                self.confirmGiftButton.alpha = 0.9
            }) { (_) in
                UIButton.animate(withDuration: 0.2, animations: {
                    self.confirmGiftButton.alpha = 1
                }) { (_) in

                    //print("VLAKNO1: \(Thread.isMainThread)")
                    self.chest.runAction(SCNAction.fadeOut(duration: 0.5),completionHandler: {
                       // print("Vlakno: \(Thread.isMainThread)")
                        self.chest.removeFromParentNode()
                        self.moveToMenu()
                    })
                    //print("VLAKNO2: \(Thread.isMainThread)")
                    self.coverAnyUIElement(element: self.confirmGiftButton)
                }
            }
        }
    }

Answer 1

所以我从这两种方法中都删除了DispatchQueue.main.async并尝试了几次，这似乎是问题所在，因为现在子视图手势识别器和按钮目标都可以在第一次单击时正确地工作。

我认为这是由于单击按钮时已经使用了Main线程，所以它以某种方式跳过了方法。并在第二次或更多次点击中起作用，因为在那个时候它已经是空的。