Swift 代码崩溃且无法正常工作

Question

在我的update(_ currentTime: TimeInterval) 函数中添加代码后，我的应用程序代码继续崩溃。有没有更好的方法来表达我的代码，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 的新手，所以我不知道如何让这段代码更有效率。帮助将不胜感激！

编辑：

速度很慢，需要数分钟才能识别得分和球位。 playerScore/comScore.text代码没有问题，在gamescene.sks中设置为0

Answer 1

我认为问题是playerScore.text 或comScore.text 可能是nil，当您尝试强制解包时应用程序崩溃。在代码中，您将值分配给func gameBegin() 中的comScore.text 和playerScore.text。但它没有在任何地方调用。尝试调用该函数可能是didMoveto view 函数。

Answer 2

我认为问题在于铸造这条线

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

相反，您必须像这样使用

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

Answer 3

关于你的崩溃，你忘记给playerScore 和comScore 赋值（你可以在didMove 函数中调用你的函数gameBegin）并且编译器可能会崩溃到该行：

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

因为comScore 文本为空。

我认为函数pointCount() 可以通过以下方式更正：

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()
            }
        }
    }

此更正仅在 computerPaddle 没有任何先前的“moveTo”执行时限制此操作的执行..