为什么 Xcode 不显示模拟器运行超时的节点？

Question

我的GameScene Swift文件中有此代码：

var background = SKSpriteNode(imageNamed: "background")
let blockImage = SKTexture(imageNamed: "block")
let blockSize = CGSize(width: 64, height: 64)
override func didMove(to view: SKView) {
    setUpGame()
}
func setUpGame(){
    background.position = CGPoint(x: frame.size.width / 2, y: frame.size.height / 2)
    addChild(background)

    let block = SKSpriteNode(texture: blockImage, size: blockSize)
    block.position.x = block.frame.width/2
    block.position.y = frame.height - block.frame.height/2
addChild(block)
}

这是我的GameController文件中的代码：

override func viewDidLoad() {
    super.viewDidLoad()
    
    if let view = self.view as! SKView? {
        // Load the SKScene from 'GameScene.sks'
        let scene = GameScene(size: self.view.bounds.size)
            // Set the scale mode to scale to fit the window
            scene.scaleMode = .aspectFill
            
            // Present the scene
            view.presentScene(scene)
    
        
        view.ignoresSiblingOrder = true
        
        view.showsFPS = true
        view.showsNodeCount = true
        
        // added to see physics body
        view.showsPhysics =  true
    }
}

为什么除了背景外，我的块节点在模拟器上出现多个运行？块最终显示后，每次运行后将继续显示，直到我编辑代码。香港专业教育学院尝试删除我的背景节点，以防万一可能是问题，但没有改变任何东西