swift - 从另一个类创建对象时，对象不会生成

Question

所以，它非常像这样:我有一个可以工作的点击手势识别器，这是 GameViewController 类中的代码:

@IBAction func handleTap(_ sender: UITapGestureRecognizer) 
{
    GameScene().makeCirc();
}

我调用的函数位于 GameScene 类中，它看起来像这样:

public func makeCirc() {

    circle = SKShapeNode (circleOfRadius: 15)
    circle.name = "white circ"
    circle.position = CGPoint (x: 0, y: 10)
    circle.fillColor = .white
    circle.physicsBody = SKPhysicsBody(circleOfRadius: 15)

    circle.physicsBody?.isDynamic = true
    circle.physicsBody?.affectedByGravity = false
    circle.physicsBody?.linearDamping = 0
    circle.physicsBody?.restitution = 1.0
    circle.physicsBody?.allowsRotation = true
    circle.physicsBody?.mass = 300
    circle.physicsBody?.density = 2*3.14*15/(circle.physicsBody?.mass)!
    circle.physicsBody?.angularDamping = 0.0

    self.addChild(circle)
    circle.physicsBody?.applyImpulse(CGVector(dx: 0.0, dy:1.0))
    print(circCount)
    circCount += 1
}

我在更新功能上还有一个计时器，这样每隔一小会儿就会产生一个球。当我点击屏幕时，还必须生成一个球。这是代码:

override func update(_ currentTime: TimeInterval)
{
    timer += 1
    if timer > spawntime {
        makeCirc()
        timer = 0
    }
    if circCount > 0 {
        if (self.childNode(withName: "white circ")?.position.y)! > self.frame.maxY - 100 {
            self.childNode(withName: "white circ")?.removeFromParent()
            circCount -= 1
        }
    }
}

然而，输出有点奇怪。不敲击时，输出是 circCount，通常是常数 12，这才是它应该的样子。然而，当我点击时，显示的 circCount 为 0，而不是生成球并使 circCount 为 13+，但是，所有对象仍然在屏幕上。

是否有办法在 circCount 不为 0 的情况下从另一个类生成球？谢谢!

<小时/>

编辑:这是 viewDidMove 函数，如果有帮助的话:

override func viewDidLoad() {
    super.viewDidLoad()
    // Load 'GameScene.sks' as a GKScene. This provides gameplay related content
    // including entities and graphs.
    self.view.isUserInteractionEnabled = true
    let tapGesture = UITapGestureRecognizer.init(target: self, action: #selector(handleTap(_:)))
    self.view.addGestureRecognizer(tapGesture)
    if let scene = GKScene(fileNamed: "GameScene") {

        // Get the SKScene from the loaded GKScene
        if let sceneNode = scene.rootNode as! GameScene? {
            // Set the scale mode to scale to fit the window
            sceneNode.scaleMode = .aspectFill

            // Present the scene
            if let view = self.view as! SKView? {
                view.presentScene(sceneNode)

                view.ignoresSiblingOrder = true

                view.showsFPS = true
                view.showsNodeCount = true
            }
        }

    }
}

Answer 1

好吧，在完成下面的操作后，一切都正常了。感谢您的帮助!

let scene = GKScene (fileNamed: "GameScene")
var instance = GameScene()
override func viewDidLoad() {
    super.viewDidLoad()
    let sceneNode = scene?.rootNode as! GameScene?
    // Load 'GameScene.sks' as a GKScene. This provides gameplay related content
    // including entities and graphs.

    let tapGesture = UITapGestureRecognizer.init(target: self, action: #selector(handleTap(_:)))
    self.view.addGestureRecognizer(tapGesture)
    self.view.isUserInteractionEnabled = true
        // Get the SKScene from the loaded GKScene
        // Set the scale mode to scale to fit the window
            sceneNode?.scaleMode = .aspectFill
            instance = (sceneNode)!
            // Present the scene
            if let view = self.view as! SKView? {
                view.presentScene(sceneNode)
                view.ignoresSiblingOrder = true
                view.showsFPS = true
                view.showsNodeCount = true


    }
}