Question

我想制作一个游戏，每次用户触摸时，它会在两个“状态”之一之间切换。为了跟踪触摸，我创建了一个名为userTouches的变量，每次用户触摸时都会从true变为false。我想这样做，如果numberOfTouches为真，它将纹理更新为state0;如果它是假的，它会将纹理更新为state1。几乎只是在每次触摸时在state0和state1之间切换。

   var userTouches: Bool = true


override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    /* Called when a touch begins */


    for touch in (touches as! Set<UITouch>) {
        userTouches = !userTouches

    }



    let centered = CGPoint(x: size.width/2, y: size.height/2)





    let state0 = SKTexture(imageNamed:"state0")


    let state1 = SKTexture(imageNamed:"state1")


    var activeState: SKSpriteNode = SKSpriteNode(texture: state0)

    //Add new state0 if it's odd, remove old state0 if it's not.
    if userTouches == true {
       activeState.texture = state0
    println("IT'S TRUE")
    } else {
        activeState.texture = state1
    println("IT'S FALSE")
    }

  self.addChild(activeState)
    activeState.name = "state0"
    activeState.xScale = 0.65
    activeState.yScale = 0.65
    activeState.position = centered

}

当我运行代码时，新的纹理会根据条件添加，但旧的纹理仍然存在。它们被添加为场景中的新spritenodes。我不想要这个。我希望它只是根据我的布尔变量在state0 spritenode的纹理（state1和activeState）之间切换。每次用户点击时，如何让我的代码在纹理之间切换，而不是将新的spritenodes堆叠在一起？

Answer 1

每次创建新对象时，更改其纹理（新对象的纹理，但不是上次设置的对象纹理）并将其添加到场景中。这就是为什么添加新对象并且旧对象没有任何反应的原因。这样做，它将解决您的问题：

在touchesBegan函数
如果你的场景中没有init，例如在didMoveToView函数创建SKSpriteNode对象并将其添加到场景中
然后在touchesBegan函数中仅将纹理设置为SKSpriteNode对象

它看起来像这样：

class GameScene: SKScene {
...
    let state0 = SKTexture(imageNamed:"state0")
    let state1 = SKTexture(imageNamed:"state1")
    var activeState: SKSpriteNode?

...
    override func didMoveToView(view: SKView) {        
        let centered = CGPoint(x: size.width/2, y: size.height/2)
        activeState = SKSpriteNode(texture: state0)
        self.addChild(activeState!)
        activeState!.name = "state0"
        activeState!.xScale = 0.65
        activeState!.yScale = 0.65
        activeState!.position = centered
    }
...
    override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
        if userTouches {
           activeState!.texture = state0
        } else {
           activeState!.texture = state1
        }
    }
...
}

使用SpriteKit删除if语句中的sprite

1 个答案: