Question

我在下面有这个代码，我只是想做一个简单的加法游戏，当你点击时打印出来的钱。我已将它设置为打印出0 + 5的currentMoney变量，依此类推，但我无法通过它更改标签。

我尝试在触摸中设置myLabel.text = String(currentMoney)，但它不会更新myLabel，我该如何实现？

import SpriteKit

var currentMoney = 0

class GameScene: SKScene {
    override func didMoveToView(view: SKView) {
        /* Setup your scene here */
        let myLabel = SKLabelNode(fontNamed:"Chalkduster")
        myLabel.text = String(currentMoney)
        myLabel.fontSize = 45
        myLabel.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame))

        self.addChild(myLabel)
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        currentMoney = currentMoney + 5
        print(currentMoney)
    }

    override func update(currentTime: CFTimeInterval) {
        /* Called before each frame is rendered */
    }
}

Answer 1

您无法更改文本，因为您无法在moveToView函数外部访问标签。试试这个：

    import SpriteKit

    var currentMoney = 0
    var myLabel: SKLabelNode! //made it globally

    class GameScene: SKScene {
        override func didMoveToView(view: SKView) {
            /* Setup your scene here */
            myLabel = SKLabelNode(fontNamed:"Chalkduster")
            myLabel.text = String(currentMoney)
            myLabel.fontSize = 45
            myLabel.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame))

        self.addChild(myLabel)
    }

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

        currentMoney = currentMoney + 5
        myLabel.text = String(currentMoney)

        print(currentMoney)
    }

Answer 2

您可以观察currentMoney变量的变化并采取适当的措施（更新标签的文本属性）。为此，您可以将标签设置为场景的属性，并使用didSet属性观察器，如下所示：

import SpriteKit

class GameScene: SKScene {

var currentMoney = 0 {

    didSet{
        myLabel.text = String(currentMoney)
    }
}

let myLabel = SKLabelNode(fontNamed:"Chalkduster")

override func didMoveToView(view: SKView) {
    /* Setup your scene here */

    myLabel.text = String(currentMoney)
    myLabel.fontSize = 45
    myLabel.position = CGPoint(x:frame.midX, y: frame.midY)

    self.addChild(myLabel)
}

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

    currentMoney = currentMoney + 5
} 
}

Answer 3

class GameScene: SKScene {

let myLabel = SKLabelNode(fontNamed:"Chalkduster")
var currentMoney = 0

override func didMoveToView(view: SKView) {
    /* Setup your scene here */
    /* Setup your scene here */

    myLabel.text = String(currentMoney)
    myLabel.fontSize = 45
    myLabel.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame))

    self.addChild(myLabel)
}

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

    currentMoney = currentMoney + 5
    print(currentMoney)

    myLabel.text = String(currentMoney)
}

override func update(currentTime: CFTimeInterval) {
    /* Called before each frame is rendered */
}


}

SpriteKit更新标签

3 个答案: