所以我有 3 个不同的障碍物，它们随机产生并在 3 秒后被移除，但是如果例如 Obstacle1 已经产生并且随机数告诉程序产生另一个 Obstacle1，我得到一个错误

"Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Attemped to add a SKNode which already has a parent"

这里是Obstacle1的代码，其他两个几乎一样只是名字不同: 函数 createObst1() { self.addChild(obst1) path = UIBezierPath(arcCenter: CGPoint(x: 0, y: -170), radius: circle.frame.size.height/2 + obst1.frame.size.width/2 - 4, startAngle: CGFloat(rad) * 2 , endAngle: CGFloat(rad) + CGFloat(M_PI * 2.5), 顺时针方向: true) 让 follow = SKAction.follow(path.cgPath, asOffset: false, orientToPath: true, duration: TimeInterval(roundDuration)) obst1.isHidden = false 让 fadeOutInstant = SKAction.fadeOut(withDuration: 0) 让 fadeIn = SKAction.fadeIn(withDuration: 0.3) 让 fadeOut = SKAction.fadeOut(withDuration: 0.3) 让 pause = SKAction.wait(forDuration: 2.4) 让 remove = SKAction.removeFromParent() 让序列 = SKAction.sequence([fadeOutInstant, fadeIn, pause, fadeOut, remove]) 让 group = SKAction.group([follow, sequence]) obst1.run(组) }

我是否必须创建多个包含相同代码的 Obstacle1 函数，还是有其他方法可以解决我的问题？

这也是我随机生成障碍物的代码，以防有帮助:func gameStarted() { Timer.scheduledTimer(timeInterval: TimeInterval(randomDelay), target: self, selector: #selector(GameScene.obstSwitch), userInfo: nil, repeats: true) }

func obstSwitch() {
let rand = arc4random_uniform(3)    
switch rand{
case 0:
    createObst1()

case 1:
    createObst2()

case 2:
    createObst3()

default:
    break
    }
}

最佳答案

试试这段代码:

class GameScene: SKScene, SKPhysicsContactDelegate {

    let obstacles = [
            SKSpriteNode(color:.brown, size:CGSize(width: 50, height: 50)),
            SKSpriteNode(color:.white, size:CGSize(width: 50, height: 50)),
            SKSpriteNode(color:.black, size:CGSize(width: 50, height: 50)),
        ]


    func getRandomObstacle(fromArray array:[SKSpriteNode])->SKSpriteNode{

        return array[Int(arc4random_uniform(UInt32(array.count)))]
    }


    func spawnObstacle(atPosition position:CGPoint) {

        if let obstacle = getRandomObstacle(fromArray: obstacles).copy() as? SKSpriteNode {

            obstacle.position = position

            //apply action that fade out and remove the node after 3 seconds

            let fadeOut = SKAction.fadeOut(withDuration: 3)
            let remove = SKAction.removeFromParent()

            let sequence = SKAction.sequence([fadeOut,remove])

            obstacle.run(sequence, withKey: "aKey")

            addChild(obstacle)

        }

    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

        if let touch = touches.first {

            let location = touch.location(in: self)
            spawnObstacle(atPosition: location)
        } 
    }  
}

这段代码基本上会在每次点击时生成一个随机障碍物的副本。因为你制作副本，所以不用担心你当前遇到的错误。

如您所说，要使用 SKAction 生成节点，作为 Timer 的替代方案，您将创建一个包含两个元素的 Action 序列、一个等待 Action 和一个生成节点的 block 。这就是 Action 序列的样子:

override func didMove(to view: SKView) {
        //Setup scene and nodes

        let wait = SKAction.wait(forDuration: 0.5)

        let spawn = SKAction.run({[unowned self] in

            //calculate obstalce initial position here, eg. randomize it

            let spawnLocation = //...
            self.spawnObstacle(atPosition: spawnLocation)
        })

        let sequence = SKAction.sequence([wait, spawn])
        let loop = SKAction.repeatForever(sequence)
        run(loop , withKey:"spawning")

    }

关于swift - 如何一次生成多个相同的 SpriteNode？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41784340/