我想知道为什么我的节点不在我的GameScene中

Question

以下是我的didMove(toView:)和我用来生成Sprite节点的函数。 忽略代码的彩色块部分，但我试图使球从原点生成并上升，我没有从代码中收到任何错误，但球未显示在视图中。 如果您能抽出宝贵时间复习我的问题，我将非常感谢。 如果您需要更清楚地说明我的问题，请提出问题。

还请考虑一下，这些球最初不在场景中，我希望在调用函数时将其添加到场景中。

class GameScene: SKScene {


var greenBlock = SKSpriteNode ()
var redBlock = SKSpriteNode ()
var blueBlock = SKSpriteNode ()
var yellowBlock = SKSpriteNode ()

var greenBall = SKSpriteNode()
var redBall = SKSpriteNode ()

var ballSpeed: TimeInterval = 4

override func didMove(to view: SKView) {

    greenBlock = self.childNode(withName: "greenBlock") as! SKSpriteNode
    redBlock = self.childNode(withName: "redBlock") as! SKSpriteNode
    blueBlock = self.childNode(withName: "blueBlock") as! SKSpriteNode
    yellowBlock = self.childNode(withName: "yellowBlock") as! SKSpriteNode

    redBall.name = "redBall"
    greenBall.name = "greenBall"

    spawnRedAndGreen()




}

func spawnRedAndGreen () {

    redBall.position = CGPoint(x: 0, y: -1)
    redBall.zPosition = 4
    addChild(redBall)


    greenBall.position = CGPoint(x: 0, y: 0)
    greenBall.zPosition = 4
    addChild(greenBall)




    let upwardsMotion = SKAction.moveTo(y: 600, duration: ballSpeed)
    let redDelay = SKAction.wait(forDuration: TimeInterval(randomBetweenNumbers(firstNum: 1, secondNum: 4)))
    let greenDelay = SKAction.wait(forDuration: TimeInterval(randomBetweenNumbers(firstNum: 1, secondNum: 3)))

    let redSequence = SKAction.sequence([upwardsMotion, redDelay])
    let greenSequence = SKAction.sequence([upwardsMotion, greenDelay])



    redBall.run(redSequence)
    greenBall.run(greenSequence)

}

这是我用来生成随机数的函数...

func randomBetweenNumbers(firstNum: CGFloat, secondNum: CGFloat) -> CGFloat {

    return CGFloat(arc4random()) / CGFloat(UINT32_MAX) * abs(firstNum - secondNum) + min(firstNum, secondNum)

}

更新的代码（注意仍然不起作用）。

class GameScene: SKScene {


var greenBlock = SKSpriteNode ()
var redBlock = SKSpriteNode ()
var blueBlock = SKSpriteNode ()
var yellowBlock = SKSpriteNode ()

var greenBall = SKSpriteNode()
var redBall = SKSpriteNode ()

var ballSpeed: TimeInterval = 4

override func didMove(to view: SKView) {

    greenBlock = self.childNode(withName: "greenBlock") as! SKSpriteNode
    redBlock = self.childNode(withName: "redBlock") as! SKSpriteNode
    blueBlock = self.childNode(withName: "blueBlock") as! SKSpriteNode
    yellowBlock = self.childNode(withName: "yellowBlock") as! SKSpriteNode


    greenBall.size = CGSize(width: 30, height: 30)
    greenBall.position = CGPoint(x: 0, y: 0)
    greenBall.zPosition = 4



    redBall.size = CGSize(width: 30, height: 30)
    redBall.position = CGPoint(x: 0, y: 0)
    redBall.zPosition = 4

    spawnRedAndGreen()

}

func spawnRedAndGreen () {

    self.addChild(greenBall)
    self.addChild(redBall)


    let upwardsMotion = SKAction.moveTo(y: 1, duration: ballSpeed)
    let redDelay = SKAction.wait(forDuration: TimeInterval(randomBetweenNumbers(firstNum: 1, secondNum: 4)))
    let greenDelay = SKAction.wait(forDuration: TimeInterval(randomBetweenNumbers(firstNum: 1, secondNum: 3)))

    let redSequence = SKAction.sequence([upwardsMotion, redDelay])
    let greenSequence = SKAction.sequence([upwardsMotion, greenDelay])



    redBall.run(redSequence)
    greenBall.run(greenSequence)

}

我还意识到，每次我调用该函数时，节点数都会增加2，但是它不会显示在屏幕上

Answer 1

您需要指定节点的大小或要使用的纹理/图像，否则它将不可见。 如果指定颜色，那也很好。

redBall.size = CGSize(width: 0.1, height: 0.1)
redBall.color = .red

同样，您的操作会强制节点快速疯狂移动（ y = 600太大，您可以将其更改为1 ），因此在上述更改之后，您只会看到闪烁。

Answer 2

解决了（感谢大家的投入，我终于开始工作了

class GameScene: SKScene {


var greenBlock = SKSpriteNode ()
var redBlock = SKSpriteNode ()
var blueBlock = SKSpriteNode ()
var yellowBlock = SKSpriteNode ()

var greenBall = SKSpriteNode()
var redBall = SKSpriteNode()

var ballSpeed: TimeInterval = 4

override func didMove(to view: SKView) {

    greenBlock = self.childNode(withName: "greenBlock") as! SKSpriteNode
    redBlock = self.childNode(withName: "redBlock") as! SKSpriteNode
    blueBlock = self.childNode(withName: "blueBlock") as! SKSpriteNode
    yellowBlock = self.childNode(withName: "yellowBlock") as! SKSpriteNode

    greenBall = SKSpriteNode(imageNamed: "greenBall")
    greenBall.size = CGSize(width: 30, height: 30)
    greenBall.position = CGPoint(x: 0, y: 0)
    greenBall.zPosition = 4



    redBall = SKSpriteNode(imageNamed: "redBall")
    redBall.size = CGSize(width: 30, height: 30)
    redBall.position = CGPoint(x: 0, y: 0)
    redBall.zPosition = 4



    spawnRedAndGreen()

}

func spawnRedAndGreen () {




    let upwardsMotion = SKAction.moveTo(y: 1000, duration: ballSpeed)
    let redDelay = SKAction.wait(forDuration: TimeInterval(randomBetweenNumbers(firstNum: 1, secondNum: 4)))
    let greenDelay = SKAction.wait(forDuration: TimeInterval(randomBetweenNumbers(firstNum: 1, secondNum: 3)))

    let redSequence = SKAction.sequence([upwardsMotion, redDelay])
    let greenSequence = SKAction.sequence([upwardsMotion, greenDelay])


    self.addChild(redBall)

    redBall.run(redSequence)

    greenBall.run(greenSequence)

}