快速点击颜色精灵后如何返回上一个场景？

Question

所以对于一个学校项目，我的任务是制作一个 2D 游戏。游戏很好，但我正在努力制作一个后退按钮（在页面中间），所以想知道是否有特定的代码可以完成这项工作。我正在使用 spriteKit，所以我试图在单击颜色精灵后返回上一个场景。

如果这是一个愚蠢的问题，我深表歉意，但我对 Swift 有点陌生。

亲切的问候， 詹姆斯

Answer 1

这是一个如何使用彩色精灵创建按钮的示例。它展示了如何设置按钮来接收触摸事件以及如何使用这些触摸事件在场景之间导航。

在此示例中，您可以向前导航到新场景并向后导航到以前的场景。

import SpriteKit

class Button: SKSpriteNode {

    var tapped: (() -> Void)?

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        tapped?()
    }

}

class GameScene: SKScene {

    var parentScene: SKScene?
    var sceneCount = 1

    override func didMove(to view: SKView) {
        if parentScene != nil {
            let backButton = addButton(color: .red, position: CGPoint(x: -200, y: 0))
            backButton.tapped = {
                if let previousScene = self.parentScene {
                    view.presentScene(previousScene)
                }
            }
        }

        let nextButton = addButton(color: .blue, position: CGPoint(x: 200, y: 0))
        nextButton.tapped = {
            if let nextScene = SKScene(fileNamed: "GameScene") as? GameScene {
                nextScene.scaleMode = self.scaleMode
                nextScene.parentScene = self
                nextScene.sceneCount = self.sceneCount + 1
                view.presentScene(nextScene)
            }
        }

        let label = SKLabelNode(text: "Scene \(sceneCount)")
        addChild(label)
    }

    func addButton(color: SKColor = .white, position: CGPoint = .zero) -> Button {
        let button = Button(color: color, size: CGSize(width: 200, height: 200))
        button.position = position
        button.isUserInteractionEnabled = true
        addChild(button)
        return button
    }

}

Answer 2

添加按钮最简单的方法是在相关的 SKScene 中检测您的精灵的触摸。

enum NodeName: String {
   case coloredSprite1
   case coloredSprite2
}

class GameScene: SKScene {

     let coloredSprite = SKSpriteNode(imageNamed: "YourImageName")

     /// Scene setup
     override func didMove(to view: SKView) {
       // set up your colored sprite if necessary
       // Give your sprites unique names to identify them

       coloredSprite.name = NodeName.coloredSprite1.rawValue // always use enums for things like string identifiers so you avoid typos
     }

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

             // Way 1 by node (probably less preferable)
             switch touchedNode {
             case coloredSprite:
                 // do something (e.g call loadScene method)
                // see below
             default: 
                 break
             }

             // Way 2 by node name (probably more preferable)
             // name is an optional so we have to unwrap it when using it in the switch statement. 
             // The easiest way is by providing an alternative string, by using the nil coalescing operator (?? "NoNodeNameFound")

             switch touchedNode.name ?? "NoNodeNameFound" {
             case NodeName.coloredSprite1.rawValue:
                // do something (e.g call loadScene method)
                // see below
             default: 
                break
             }
        }
    }

    // Also call touchesEnded, touchesMoved and touchesCancelled and do necessary stuff
}

对于更可重用的解决方案，您最好创建一个按钮子类。谷歌有很多关于如何做到这一点的教程。

为了在 SKScene 之间转换，您可以在每个场景中创建一个 loadScene 方法，然后在必要时调用它们。

// Start Scene
class StartScene: SKScene {
   ...

   func loadGameScene() {

        // If you do everything in code
        let gameScene = GameScene(size: self.size)
        view?.presentScene(gameScene, transition: ...)

        // If you use SpriteKit scene editor
        guard let gameScene = SKScene(fileNamed: "GameScene") else { return } // fileNamed is the name you gave the .sks file
        view?.presentScene(gameScene, transition: ...)
   }
}

// Game scene
class GameScene: SKScene {
     ....

     func loadStartScene() {
        // If you do everything in code
        let startScene = StartScene(size: self.size)
        view?.presentScene(startScene, transition: ...)

        // If you use SpriteKit scene editor
        guard let startScene = SKScene(fileNamed: "StartScene") else { return } // fileNamed is the name you gave the .sks file
        view?.presentScene(startScene, transition: ...)
   }
}

希望对你有帮助