Swift code crashing and not working

Question

将代码添加到我的update(_ currentTime: TimeInterval)函数后，我的应用程序的代码继续崩溃。有没有更好的方式来表达我的代码，使其不会崩溃？

import SpriteKit 
import GameplayKit 

class GameScene: SKScene { 

var startScreen = SKSpriteNode() 
var Ball = SKSpriteNode() 
var playerPaddle = SKSpriteNode() 
var computerPaddle = SKSpriteNode() 
var playerScore = SKLabelNode() 
var comScore = SKLabelNode() 

override func didMove(to view: SKView) { 

    startScreen = childNode(withName: "startScreen") as! SKSpriteNode 
    Ball = childNode(withName: "Ball") as! SKSpriteNode 
    playerPaddle = childNode(withName: "playerPaddle") as! SKSpriteNode 
    computerPaddle = childNode(withName: "computerPaddle") as! SKSpriteNode 
    playerScore = childNode(withName: "playerScore") as! SKLabelNode 
    comScore = childNode(withName: "comScore") as! SKLabelNode 

    let bodyBorder = SKPhysicsBody(edgeLoopFrom: self.frame) 
    bodyBorder.friction = 0 
    bodyBorder.restitution = 1 
    self.physicsBody = bodyBorder 

    Ball.physicsBody?.applyImpulse(CGVector(dx:20, dy:10)) 
} 

func gameBegin() { 
    playerScore.text = String(0) 
    comScore.text = String(0) 
} 

func playerPoint() { 
    var comScoreInt: Int = Int(comScore.text!)! 
    comScoreInt += 1 
    comScore.text = String(comScoreInt) 
    Ball.position = (CGPoint(x:0, y:0)) 
    Ball.physicsBody?.applyImpulse(CGVector(dx:-20,dy:-10)) 
} 

func comPoint() { 
    var playerScoreInt: Int = Int(playerScore.text!)! 
    playerScoreInt += 1 
    playerScore.text = String(playerScoreInt) 
    Ball.physicsBody?.applyImpulse(CGVector(dx:20,dy:10)) 
    Ball.position = (CGPoint(x:0, y:0)) 

} 

func pointCount() { 
    computerPaddle.run(SKAction.moveTo(y: Ball.position.y, duration: 0.5)) 
    if Ball.position.x <= playerPaddle.position.x - 42 { 
     playerPoint() 
    } else if Ball.position.x >= computerPaddle.position.x + 42 { 
     comPoint() 
    } 

} 

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { 
    for touch in touches { 
     let location = touch.location(in: self) 

     playerPaddle.run(SKAction.moveTo(y: location.y, duration: 0.1)) 
    } 
} 

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

     playerPaddle.run(SKAction.moveTo(y: location.y, duration: 0)) 
    } 
} 


override func update(_ currentTime: TimeInterval) { 
    pointCount() 
} 
} 

我是SpriteKit的新用户，因此我不知道如何让此代码更加有效。帮助将不胜感激！

编辑：

的速度很慢，而且可能需要几夭议事录承认一点成绩，和球的位置。没有什么不对的playerScore/comScore.text代码，它被设置为0 gamescene.sks

Answer 1

我相信问题是playerScore.text或comScore.text可能是nil和应用程序崩溃，当您尝试强行解开它。在代码中，您将func gameBegin()中的值分配给comScore.text和playerScore.text。但它并没有被称为任何地方。尝试调用该函数可能是didMoveto view函数。

Answer 2

我认为问题是出在铸造这一行

Int(playerScore.text!)! and Int(comScore.text!)! 

相反，你必须使用这样

Int(comScore.text?) ?? 0 
Int(playerScore.text?) ?? 0 

Answer 3

关于你的崩溃，你已经忘了给一个值playerScore和comScore（你可以调用函数中的函数gameBegin），编译器可能会崩溃到该行：

var comScoreInt: Int = Int(comScore.text!)! 

因为comScore文本为空。

我觉得功能pointCount()可以与纠正：

func pointCount() { 
     if computerPaddle.action(forKey: "moveTo") == nil { 
      computerPaddle.run(SKAction.moveTo(y: Ball.position.y, duration: 0.5), withKey:"moveTo") 
      if Ball.position.x <= playerPaddle.position.x - 42 { 
       playerPoint() 
      } else if Ball.position.x >= computerPaddle.position.x + 42 { 
       comPoint() 
      } 
     } 
    } 

该修正限制这个动作的执行，只有当computerPaddle没有任何先前的“的moveTo”的执行..