ios - 如何使用 SpriteKit 的 SKAction 为 SKSpriteNode 创建时间间隔？

Question

我有一个函数，篮球。我希望能够以固定的时间间隔在屏幕顶部的 CGPoint(515,700) 处生成我的 basketBall 节点。我知道唯一可以完成等待几秒钟的方法是 sleep();然而，sleep() 显然不允许 SpriteNodes 保留在屏幕上，所以我需要一个替代方案。

我发现了 NSTimeInterval，但我宁愿避免导入 Foundation。我认为 SKAction 允许时间通过 waitForDuration()，但我很困惑它是如何工作的。有人可以阐明 SpriteKit 的 SKAction 吗？

override func didMoveToView(view: SKView) {

    let basketBall = SKSpriteNode(imageNamed: "basketball")
    let waitForObjects = SKAction.waitForDuration(3)
    let basketBallFalls = SKAction.runBlock({
        self.Basketball()
    })
    let action = SKAction.sequence([waitForObjects, basketBallFalls])


    SKAction.runAction(action, onChildWithName: "basketball")
    SKAction.repeatActionForever(action)
    //Basketball()
}

func Basketball(){

    basketBall.position = CGPointMake(515, 700)
    basketBall.size = CGSizeMake(50, 50)
    basketBall.size = CGSize(width: 50.0, height: 50.0)
    basketBall.zPosition = 10
    basketBall.physicsBody = SKPhysicsBody(circleOfRadius: 25.0)
    basketBall.physicsBody?.mass = 0.8
    basketBall.physicsBody?.restitution = 0.6
    basketBall.physicsBody?.dynamic = true


    self.addChild(basketBall)
}

Answer 1

尝试使用SKAction.waitForDuration(_:) .

例。像这样:

let waitDuration = NSTimeInterval(arc4random_uniform(20))

let waitAction = SKAction.waitForDuration(waitDuration)
let ballAction = SKAction.runBlock(self.Basketball) //call your function

runAction(SKAction.sequence([waitAction, ballAction]))