快速点击彩色精灵后如何返回上一场景？

Question

因此，对于一个学校项目，我要负责制作2D游戏。 这款游戏还不错，但是我在如何制作后退按钮（在页面的中间）方面很挣扎，因此想知道是否有特定的代码可以实现此功能。 我正在使用spriteKit，因此在单击彩色Sprite后尝试返回上一场景。

如果这是一个愚蠢的问题，我深表歉意，但是我对Swift还是有点陌生​​。

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。 它显示了如何设置一个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，您可以向前导航至新场景，然后向后导航至先前场景。

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

太添加按钮最简单的方法是检测相关SKScene中子画面上的触摸。

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，理想情况下，您希望创建一个按钮子类。 谷歌上有很多关于如何做到这一点的教程。

要在SKScenes之间进行过渡，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: ...)
   }
}

希望这可以帮助