如何在Singleton的快速Sprite Kit游戏中显示分数标签

Question

I have been trying for a couple of days now to implement a singleton method to update the score for each level of a game I am making. I cannot figure out the correct way to implement it. I have no errors when I build and run the project, but the Score Label will not display when I run the game. I have no idea why, but I know it has something to do with the singleton method not being implemented correctly. Any input would be much appreciated. The code below is my first and opening scene that does not show the score label or score as of right now.

This is the first level of the game:

import SpriteKit

class Singleton {

static let sharedInstance = Singleton()
var ScoreLabel = UILabel()
var Score : Int = 0


}



struct PhysicsCategory {
static let Enemy : UInt32 = 1
static let Bullet : UInt32 = 2
static let Player : UInt32 = 3
}



class GameScene: SKScene, SKPhysicsContactDelegate {
var HighScore = Int()
var Player = SKSpriteNode(imageNamed: "GoodGuy.png")
var Level1Label = UILabel()


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

    var timer = NSTimer.scheduledTimerWithTimeInterval(5.0, target: self, selector: "update", userInfo: nil, repeats: true)

    var HighScoreDefault = NSUserDefaults.standardUserDefaults()
    if (HighScoreDefault.valueForKey("HighScore") != nil){

        HighScore = HighScoreDefault.valueForKey("HighScore") as! NSInteger
    }
    else{
        HighScore = 0
    }




    physicsWorld.contactDelegate = self

    self.scene?.backgroundColor = UIColor.blackColor()

    self.scene?.size = CGSize(width:640, height: 1136)

    self.addChild(SKEmitterNode(fileNamed: "MagicParticle")!)

    Player.position = CGPointMake(self.size.width/2, self.size.height/8)
    Player.physicsBody = SKPhysicsBody (rectangleOfSize: Player.size)
    Player.physicsBody?.affectedByGravity = false
    Player.physicsBody?.categoryBitMask = PhysicsCategory.Player
    Player.physicsBody?.contactTestBitMask = PhysicsCategory.Enemy
    Player.physicsBody?.dynamic = false

    Level1Label = UILabel (frame: CGRect(x:0, y:0, width: view.frame.size.width/3, height: 30))
    Level1Label.center = CGPoint(x: view.frame.size.width/1.675 , y: view.frame.size.height/1.05)
    Level1Label.textColor = UIColor.whiteColor()
    Level1Label.text = "Level 1"
    self.view?.addSubview(Level1Label)

    Singleton.sharedInstance.ScoreLabel.text = "\(Singleton.sharedInstance.Score)"
    Singleton.sharedInstance.ScoreLabel = UILabel(frame: CGRect(x:0, y:0, width:100, height:20))
    Singleton.sharedInstance.ScoreLabel.backgroundColor = UIColor.clearColor()
    Singleton.sharedInstance.ScoreLabel.textColor = UIColor.whiteColor()
    self.view?.addSubview(Singleton.sharedInstance.ScoreLabel)


    var Timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("SpawnBullets"), userInfo: nil, repeats: true)

    var Enemytimer = NSTimer.scheduledTimerWithTimeInterval(1.5, target: self, selector: Selector("SpawnEnemies"), userInfo: nil, repeats: true)



    self.addChild(Player)





}

func update() {
    self.view?.presentScene(GameScene2())
    Level1Label.removeFromSuperview()
}

func didBeginContact(contact: SKPhysicsContact) {
    var firstBody : SKPhysicsBody = contact.bodyA
    var secondBody : SKPhysicsBody = contact.bodyB
    if ((firstBody.categoryBitMask == PhysicsCategory.Enemy) && (secondBody.categoryBitMask == PhysicsCategory.Bullet) ||
        (firstBody.categoryBitMask == PhysicsCategory.Bullet) && (secondBody.categoryBitMask == PhysicsCategory.Enemy)){

        CollisionWithBullet(firstBody.node as! SKSpriteNode, Bullet: secondBody.node as! SKSpriteNode)

    }

    else if ((firstBody.categoryBitMask == PhysicsCategory.Enemy) && (secondBody.categoryBitMask == PhysicsCategory.Player) ||
        (firstBody.categoryBitMask == PhysicsCategory.Player) && (secondBody.categoryBitMask == PhysicsCategory.Enemy)){

            CollisionWithPlayer(firstBody.node as! SKSpriteNode, Player: secondBody.node as! SKSpriteNode)
    }


}


func CollisionWithBullet(Enemy: SKSpriteNode, Bullet: SKSpriteNode){
    Enemy.removeFromParent()
    Bullet.removeFromParent()
    Singleton.sharedInstance.Score++


    Singleton.sharedInstance.ScoreLabel.text = "\(Singleton.sharedInstance.Score)"
}



func CollisionWithPlayer(Enemy: SKSpriteNode, Player: SKSpriteNode){
    var ScoreDefault = NSUserDefaults.standardUserDefaults()
    ScoreDefault.setValue(Singleton.sharedInstance.Score, forKey: "Score")
    ScoreDefault.synchronize()


    if (Singleton.sharedInstance.Score > HighScore){

    var HighScoreDefault = NSUserDefaults.standardUserDefaults()
    HighScoreDefault.setValue(Singleton.sharedInstance.Score, forKey: "HighScore")

    }


    Enemy.removeFromParent()
    Player.removeFromParent()
    self.view?.presentScene(EndScene())
    Level1Label.removeFromSuperview()

        }

func SpawnBullets(){
    var Bullet = SKSpriteNode(imageNamed: "Bullet.png")
    Bullet.zPosition = -5
    Bullet.position = CGPointMake(Player.position.x, Player.position.y)

    let action = SKAction.moveToY(self.size.height + 30, duration: 1.0)
    let actionDone = SKAction.removeFromParent()
    Bullet.runAction(SKAction.sequence([action, actionDone]))


    Bullet.physicsBody = SKPhysicsBody(rectangleOfSize: Bullet.size)
    Bullet.physicsBody?.categoryBitMask = PhysicsCategory.Bullet
    Bullet.physicsBody?.contactTestBitMask = PhysicsCategory.Enemy
    Bullet.physicsBody?.affectedByGravity = false
    Bullet.physicsBody?.dynamic = false
    self.addChild(Bullet)
}

func SpawnEnemies(){
    var Enemy = SKSpriteNode(imageNamed: "BadGuy.png")
    var MinValue = self.size.width/8
    var MaxValue = self.size.width - 150
    let SpawnPoint = UInt32(MaxValue - MinValue)
    Enemy.position = CGPoint(x: CGFloat(arc4random_uniform(SpawnPoint)), y: self.size.height)
    Enemy.physicsBody = SKPhysicsBody(rectangleOfSize: Enemy.size)
    Enemy.physicsBody?.categoryBitMask = PhysicsCategory.Enemy
    Enemy.physicsBody?.contactTestBitMask = PhysicsCategory.Bullet
    Enemy.physicsBody?.affectedByGravity = false
    Enemy.physicsBody?.dynamic = true

    let action = SKAction.moveToY(-70, duration: 3.0)
    let actionDone = SKAction.removeFromParent()
    Enemy.runAction(SKAction.sequence([action, actionDone]))

    Enemy.runAction(SKAction.repeatActionForever(action))

    self.addChild(Enemy)

}



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

    for touch in touches {
        let location = touch.locationInNode(self)

        Player.position.x = location.x

    }
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
    for touch in touches {
        let location = touch.locationInNode(self)

        Player.position.x = location.x

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

This is the second level of the game:

import SpriteKit

struct PhysicsCategory2 {
static let Enemy : UInt32 = 1//00000000000000000000000000000001
static let Bullet : UInt32 = 2//00000000000000000000000000000010
static let Player : UInt32 = 3//00000000000000000000000000000100
}


class GameScene2: SKScene, SKPhysicsContactDelegate {
var HighScore = Int()
var Player = SKSpriteNode(imageNamed: "GoodGuy.png")
var Level2Label = UILabel()


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

    var HighScoreDefault = NSUserDefaults.standardUserDefaults()
    if (HighScoreDefault.valueForKey("HighScore") != nil){

        HighScore = HighScoreDefault.valueForKey("HighScore") as! NSInteger
    }
    else{
        HighScore = 0
    }



    physicsWorld.contactDelegate = self

    self.scene?.backgroundColor = UIColor.blackColor()

    self.scene?.size = CGSize(width:640, height: 1136)

    self.addChild(SKEmitterNode(fileNamed: "MagicParticle")!)

    Player.position = CGPointMake(self.size.width/2, self.size.height/8)
    Player.physicsBody = SKPhysicsBody (rectangleOfSize: Player.size)
    Player.physicsBody?.affectedByGravity = false
    Player.physicsBody?.categoryBitMask = PhysicsCategory2.Player
    Player.physicsBody?.contactTestBitMask = PhysicsCategory2.Enemy
    Player.physicsBody?.dynamic = false

    Level2Label = UILabel (frame: CGRect(x:0, y:0, width: view.frame.size.width/3, height: 30))
    Level2Label.center = CGPoint(x: view.frame.size.width/1.675 , y: view.frame.size.height/1.05)
    Level2Label.textColor = UIColor.whiteColor()
    Level2Label.text = "Level 2"
    self.view?.addSubview(Level2Label)


    var Timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("SpawnBullets"), userInfo: nil, repeats: true)

    var Enemytimer = NSTimer.scheduledTimerWithTimeInterval(1.5, target: self, selector: Selector("SpawnEnemies"), userInfo: nil, repeats: true)



    self.addChild(Player)

    Singleton.sharedInstance.ScoreLabel.text = "\(Singleton.sharedInstance.Score)"
    Singleton.sharedInstance.ScoreLabel = UILabel(frame: CGRect(x:0, y:0, width:100, height:20))
    Singleton.sharedInstance.ScoreLabel.backgroundColor = UIColor.clearColor()
    Singleton.sharedInstance.ScoreLabel.textColor = UIColor.whiteColor()



}

func didBeginContact(contact: SKPhysicsContact) {
    var firstBody : SKPhysicsBody = contact.bodyA
    var secondBody : SKPhysicsBody = contact.bodyB
    if ((firstBody.categoryBitMask == PhysicsCategory2.Enemy) && (secondBody.categoryBitMask == PhysicsCategory2.Bullet) ||
        (firstBody.categoryBitMask == PhysicsCategory2.Bullet) && (secondBody.categoryBitMask == PhysicsCategory2.Enemy)){

            CollisionWithBullet(firstBody.node as! SKSpriteNode, Bullet: secondBody.node as! SKSpriteNode)

    }

    else if ((firstBody.categoryBitMask == PhysicsCategory2.Enemy) && (secondBody.categoryBitMask == PhysicsCategory2.Player) ||
        (firstBody.categoryBitMask == PhysicsCategory2.Player) && (secondBody.categoryBitMask == PhysicsCategory2.Enemy)){

            CollisionWithPlayer(firstBody.node as! SKSpriteNode, Player: secondBody.node as! SKSpriteNode)
    }


    }


    func CollisionWithBullet(Enemy: SKSpriteNode, Bullet: SKSpriteNode){
    Enemy.removeFromParent()
    Bullet.removeFromParent()
    Singleton.sharedInstance.Score++


    Singleton.sharedInstance.ScoreLabel.text = "\(Singleton.sharedInstance.Score)"
}




func CollisionWithPlayer(Enemy: SKSpriteNode, Player: SKSpriteNode){
    var ScoreDefault = NSUserDefaults.standardUserDefaults()
    ScoreDefault.setValue(Singleton.sharedInstance.Score, forKey: "Score")
    ScoreDefault.synchronize()

    if (Singleton.sharedInstance.Score > HighScore){

        var HighScoreDefault = NSUserDefaults.standardUserDefaults()
        HighScoreDefault.setValue(Singleton.sharedInstance.Score, forKey: "HighScore")

    }


    Enemy.removeFromParent()
    Player.removeFromParent()
    self.view?.presentScene(EndScene())
    Level2Label.removeFromSuperview()
    Singleton.sharedInstance.ScoreLabel.removeFromSuperview()

    }

    func SpawnBullets(){
    var Bullet = SKSpriteNode(imageNamed: "Bullet.png")
    Bullet.zPosition = -5
    Bullet.position = CGPointMake(Player.position.x, Player.position.y)

    let action = SKAction.moveToY(self.size.height + 30, duration: 1.0)
    let actionDone = SKAction.removeFromParent()
    Bullet.runAction(SKAction.sequence([action, actionDone]))


    Bullet.physicsBody = SKPhysicsBody(rectangleOfSize: Bullet.size)
    Bullet.physicsBody?.categoryBitMask = PhysicsCategory2.Bullet
    Bullet.physicsBody?.contactTestBitMask = PhysicsCategory2.Enemy
    Bullet.physicsBody?.affectedByGravity = false
    Bullet.physicsBody?.dynamic = false
    self.addChild(Bullet)
    }

    func SpawnEnemies(){
    var Enemy = SKSpriteNode(imageNamed: "BadGuy.png")
    var MinValue = self.size.width/8
    var MaxValue = self.size.width - 150
    let SpawnPoint = UInt32(MaxValue - MinValue)
    Enemy.position = CGPoint(x: CGFloat(arc4random_uniform(SpawnPoint)), y: self.size.height)
    Enemy.physicsBody = SKPhysicsBody(rectangleOfSize: Enemy.size)
    Enemy.physicsBody?.categoryBitMask = PhysicsCategory2.Enemy
    Enemy.physicsBody?.contactTestBitMask = PhysicsCategory2.Bullet
    Enemy.physicsBody?.affectedByGravity = false
    Enemy.physicsBody?.dynamic = true

    let action = SKAction.moveToY(-70, duration: 3.0)
    let actionDone = SKAction.removeFromParent()
    Enemy.runAction(SKAction.sequence([action, actionDone]))

    Enemy.runAction(SKAction.repeatActionForever(action))

    self.addChild(Enemy)

    }



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

    for touch in touches {
        let location = touch.locationInNode(self)

        Player.position.x = location.x

    }
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
    for touch in touches {
        let location = touch.locationInNode(self)

        Player.position.x = location.x

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

This is the Game Over page of the game:

import Foundation
import SpriteKit

class EndScene: SKScene {

var RestartButton : UIButton!
var HighScore : Int!
var HighScoreLabel : UILabel!
var GameOverLabel : UILabel!
override func didMoveToView(view: SKView) {

    self.scene?.backgroundColor = UIColor.blackColor()

    self.scene?.size = CGSize(width:640, height: 1136)

    self.addChild(SKEmitterNode(fileNamed: "MagicParticle")!)

    RestartButton = UIButton(frame: CGRect(x:0, y:0, width: view.frame.size.width/3
        , height: 30))
    RestartButton.titleLabel?.adjustsFontSizeToFitWidth = true
    RestartButton.center = CGPoint(x: view.frame.size.width/2 , y: view.frame.size.height/1.5)
    RestartButton.setTitle("Restart", forState: UIControlState.Normal)
    RestartButton.showsTouchWhenHighlighted = true
    RestartButton.setTitleColor(UIColor.whiteColor(), forState:  UIControlState.Normal)
    RestartButton.addTarget(self, action: Selector("Restart"), forControlEvents: UIControlEvents.TouchUpInside)
    self.view?.addSubview(RestartButton)

    var ScoreDefault = NSUserDefaults.standardUserDefaults()
    var Score = ScoreDefault.valueForKey("Score") as! NSInteger

    var HighScoreDefault = NSUserDefaults.standardUserDefaults()
    HighScore = HighScoreDefault.valueForKey("HighScore") as! NSInteger

    Singleton.sharedInstance.ScoreLabel = UILabel (frame: CGRect(x:0, y:0, width: view.frame.size.width/3, height: 30))
    Singleton.sharedInstance.ScoreLabel.center = CGPoint(x: view.frame.size.width/1.6 , y: view.frame.size.height/2.5)
    Singleton.sharedInstance.ScoreLabel.text = "\(Singleton.sharedInstance.Score)"
    Singleton.sharedInstance.ScoreLabel.textColor = UIColor.whiteColor()
    self.view?.addSubview(Singleton.sharedInstance.ScoreLabel)

    HighScoreLabel = UILabel (frame: CGRect(x:0, y:0, width: view.frame.size.width/3, height: 30))
    HighScoreLabel.center = CGPoint(x: view.frame.size.width/1.6 , y: view.frame.size.height/2)
    HighScoreLabel.textColor = UIColor.whiteColor()
    HighScoreLabel.text = "\(HighScore)"
    self.view?.addSubview(HighScoreLabel)

    GameOverLabel = UILabel (frame: CGRect(x:0, y:0, width: view.frame.size.width/3.8, height: 30))
    GameOverLabel.center = CGPoint(x: view.frame.size.width/2 , y: view.frame.size.height/10)
    GameOverLabel.textColor = UIColor.whiteColor()
    GameOverLabel.text = "Game Over"
    self.view?.addSubview(GameOverLabel)

}

func Restart(){
    self.view?.presentScene(GameScene(), transition: SKTransition.crossFadeWithDuration(0.3))
    RestartButton.removeFromSuperview()
    HighScoreLabel.removeFromSuperview()
    Singleton.sharedInstance.ScoreLabel.removeFromSuperview()
    GameOverLabel.removeFromSuperview()

}
}

I guess a new question would be if there is something else I need to do in order to make the singleton method work from scene to scene other than change the names of the variables

Answer 1

Where do you call DisplayGameScore() ? (you don't)

Other then that, this is no so good

static let ScoreLabel = Singleton()
static let Score = Singleton()

you created two instances of Singleton which is wrong

and then you have instance variable with the same name ScoreLabel which is also not so good

Answer 2

As others have said you create 2 singletons.

To use it correctly you should only do this in your singleton class

static let sharedInstance = Singelton()

And than to use your score property or other properties/methods in your game scenes you would say this

Singleton.sharedInstance.score++ 
Singleton.sharedInstance.scoreLabel ...
Singleton.sharedInstance.displayGameScore()

You could also write it like this in GameScene

 let singleton = Singleton.sharedInstance
 singleton.score++
 singleton.scoreLabel...
 singleton.displayGameScore()

As a side note it's best practice to write your properties/methods like this

var score...
func displayGameScore()...

not

var Score....
func DisplayGameScore() ...

As another side note you should probably use SpriteKit Apis if you use it, so instead of UILabel you should use SKLabelNodes. Furthermore the display gameScore method can probably go into your GameScene and than you just reference the score property from your Singleton.