Swift 错误：无法调用非函数类型“SKSpriteNode”的值

Posted 2023-03-14

【中文标题】Swift 错误：无法调用非函数类型“SKSpriteNode”的值

【英文标题】：Swift error: Cannot call value of non-function type "SKSpriteNode"

【发布时间】：2016-02-06 14:51:23

【问题描述】：

我试图将 Swift 1 中的 this github 代码翻译成 Swift 2。这使得像 this video 中的绳子一样。

我翻译的 Rope.swift 完成后看起来像这样：

//
//  Rope.swift
//  SKSwiftRopeDemo
//
//  Created by Jeremy Higgins on 6/10/14.
//  Copyright (c) 2014 Digital Buckeye. All rights reserved.
//

import SpriteKit

class Rope : SKNode 

    var ropeTexture : String
    var node1 : SKNode
    var node2 : SKNode
    var parentScene : SKScene

    init(parentScene scene : SKScene, node node1 : SKNode, node node2 : SKNode, texture tex : String) 

        self.ropeTexture = tex
        self.node1 = node1
        self.node2 = node2
        self.parentScene = scene

        super.init()
        self.name = "rope"

        self.createRope()
    

    required init(coder aDecoder: NSCoder) 
        fatalError("init(coder:) has not been implemented")
    

    func createRope() 
        // Calculate distance & angle

        let deltaX = node2.position.x - node1.position.x
        let deltaY = node2.position.y - (node1.position.y  + (node1.frame.size.height / 2))
        let total = deltaX * deltaX + deltaY * deltaY
        let distance = Float(sqrtf(Float(total)))
        let height = Float(SKSpriteNode(imageNamed: "Rope").size.height - 1.0)
        let p = (distance / height)

        var points = Int(p)
        points -= 1;

        let vX = CGFloat(deltaX) / CGFloat(points)
        let vY = CGFloat(deltaY) / CGFloat(points)

        let vector = CGPoint(x: vX, y: vY)
        var previousNode : SKSpriteNode?
        let angle = atan2f(Float(deltaY), Float(deltaX))

        for i in 0...points 
            var x = self.node1.position.x
            var y = self.node1.position.y + (self.node1.frame.size.height / 2)

            y += vector.y * CGFloat(i)
            x += vector.x * CGFloat(i)

            let ropePiece = SKSpriteNode(imageNamed: self.ropeTexture)
            ropePiece.name = "rope"
            ropePiece.position = CGPoint(x: x, y: y)
            ropePiece.zRotation = CGFloat(angle + 1.57)
            ropePiece.zPosition = -1

            ropePiece.physicsBody = SKPhysicsBody(rectangleOfSize: ropePiece.size)

            ropePiece.physicsBody?.collisionBitMask = 2
            ropePiece.physicsBody?.categoryBitMask = 2
            ropePiece.physicsBody?.contactTestBitMask = 2

            self.parentScene.addChild(ropePiece)

            if let pNode = previousNode 
                let pin = SKPhysicsJointPin.jointWithBodyA(pNode.physicsBody!, bodyB: ropePiece.physicsBody!, anchor: CGPoint(x: CGRectGetMidX(ropePiece.frame), y: CGRectGetMidY(ropePiece.frame)))
                self.parentScene.physicsWorld.addJoint(pin)
             else 
                if i == 0 
                    let pin = SKPhysicsJointPin.jointWithBodyA(self.node1.physicsBody!, bodyB: ropePiece.physicsBody!, anchor: CGPoint(x: CGRectGetMidX(self.node1.frame), y: CGRectGetMaxY(self.node1.frame)))
                    self.parentScene.physicsWorld.addJoint(pin)
                
            

            previousNode = ropePiece
        

        if let pNode = previousNode 
            let pin = SKPhysicsJointPin.jointWithBodyA(self.node2.physicsBody!, bodyB: pNode.physicsBody!, anchor: CGPoint(x: CGRectGetMidX(pNode.frame), y: CGRectGetMidY(pNode.frame)))
            self.parentScene.physicsWorld.addJoint(pin)
        
    

    func destroyRope() 
        self.parentScene.enumerateChildNodesWithName("rope", usingBlock:  node, stop in
            node.removeFromParent()
        )
    

GameScene.swift 部分变成了这样：

//
//  GameScene.swift
//  Hop Hope
//
//  Created by Sergio on 5/2/16.
//  Copyright (c) 2016. All rights reserved.
//

import SpriteKit

struct PhysicsCategory 
    static let Player : UInt32 = 0x1 << 1
    static let Ground : UInt32 = 0x1 << 2
    static let Rope : UInt32 = 0x1 << 3


class GameScene: SKScene 

    var Ground = SKSpriteNode()

    var Rope = SKSpriteNode()

    var Player = SKSpriteNode()
    let szPlayer = 60

    var anchor = SKSpriteNode()
    var aplayer = SKSpriteNode()


    override func didMoveToView(view: SKView) 
        // Physics border around screen
        self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame)

        // Static Body
        self.anchor = SKSpriteNode(color: UIColor.redColor(), size: CGSize(width: 50, height: 50))
        self.anchor.position = CGPoint(x: self.frame.size.width / 2, y: self.frame.size.height - anchor.size.height)
        self.anchor.physicsBody = SKPhysicsBody(rectangleOfSize: anchor.frame.size)
        self.anchor.physicsBody?.dynamic = false
        self.anchor.physicsBody?.collisionBitMask = 1
        self.anchor.physicsBody?.categoryBitMask = 1
        self.anchor.physicsBody?.contactTestBitMask = 1
        self.addChild(self.anchor)

        // Dynamic Body
        self.aplayer = SKSpriteNode(color: UIColor.greenColor(), size: CGSize(width: 50, height: 50))
        self.aplayer.position = CGPoint(x: aplayer.size.width * 2, y: self.frame.size.height / 2)
        self.aplayer.physicsBody = SKPhysicsBody(rectangleOfSize: aplayer.frame.size)
        self.aplayer.physicsBody?.collisionBitMask = 1
        self.aplayer.physicsBody?.categoryBitMask = 1
        self.aplayer.physicsBody?.contactTestBitMask = 1
        self.addChild(self.aplayer)

        // Create Rope
        var rope = Rope(parentScene: self, node: self.aplayer, node: self.anchor, texture: "Rope")


        var label = SKLabelNode(text: "Tap on screen to move block")
        label.fontColor = UIColor.blackColor()
        label.position = CGPoint(x: self.frame.size.width / 2, y: 200)
        self.addChild(label)

        ////////////////////////////////// rest of the code

问题是var rope = Rope(parentScene: self, node: self.aplayer, node: self.anchor, texture: "Rope")给出错误Cannot call value of non-function type "SKSpriteNode"

这是唯一的错误，其余的代码和文件都很好，我不知道如何解决这个问题。我已经尝试将 Rope.swift 中的所有 SKNodes 更改为 SKSpriteNode，但这只会产生更多错误。

【问题讨论】：

您的问题是您有一个名为Rope 的var。见var Rope = SKSpriteNode()。

哦，谢谢！我删除了那行，但现在当我运行它时，屏幕变为白色，var anchor = SKSpriteNode() 以绿色突出显示“线程 1：断点 2.5”...我该怎么办？

是不是不小心设置了断点？如果该行旁边有一个蓝色箭头，请控制单击它并将其删除。

哦，是的！我不知道它们是做什么用的，我昨天刚开始使用 Xcode，但是您帮了很多忙，谢谢！如果你愿意，你可以用你所说的来回答这个问题

【参考方案1】：

您已经声明了一个名为 Rope 的变量以及一个名为 Rope 的类：

var Rope = SKSpriteNode()

所以，当您稍后创建绳索时：

var rope = Rope(parentScene: self, node: self.aplayer, node: self.anchor, texture: "Rope")

Swift 认为您正在尝试将变量 Rope 用作函数指针，而 SKSpriteNode 则无法做到这一点。

注意：您应该为变量使用以小写字母开头的名称，为类和结构使用以大写字母开头的名称。如果你遵守了这个约定，你就不会遇到这个问题。