无法在Sprite Kit中移动对象

Question

我正在尝试制作一款泡泡射击游戏，但我无法移动我的划桨。知道为什么会这样吗？

//
//  GameScene.swift
//  gggame
//
//  Created by divy on 6/17/15.
//  Copyright (c) 2015 divy. All rights reserved.
//

 import SpriteKit

 class GameScene: SKScene , SKPhysicsContactDelegate {

     var istouchingpaddle = false
     let ballcat: UInt32 = 0x1 << 0

     let paddlecat : UInt32 = 0x1 << 1

     override func didMoveToView(view: SKView) {



         let border = SKPhysicsBody(edgeLoopFromRect: self.frame)
         border.friction = 0
         self.physicsBody = border
         self.physicsWorld.gravity = (CGVectorMake(0,-9.8))
         self.physicsWorld.contactDelegate = self

         //ball setting

         let ball = childNodeWithName("ball") as SKSpriteNode
         ball.physicsBody?.applyImpulse(CGVectorMake(30, -30))
         ball.physicsBody?.allowsRotation = false
         ball.physicsBody?.friction = 0
         ball.physicsBody?.restitution = 1
         ball.physicsBody?.angularDamping = 0
         ball.physicsBody?.linearDamping = 0
         ball.physicsBody?.categoryBitMask = ballcat


     }


     func didBeginContact(contact: SKPhysicsContact) {

     }

     override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {

         //touch setting

         var touch = touches.anyObject() as UITouch!
         var location = touch.locationInNode(self)
         if let body = self.physicsWorld.bodyAtPoint(location)

         {
             if body.node!.name == "paddle"
             {
                 istouchingpaddle = true
             }

         }

     }

     override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
         istouchingpaddle = false
     }

     override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
         if istouchingpaddle{
             var touch = touches.anyObject() as UITouch!
             var currentlocation = touch.locationInNode(self)
             var prevlocation = touch.locationInNode(self)
             var paddle = childNodeWithName("paddle") as SKSpriteNode



             var xpos = paddle.position.x + (currentlocation.x - prevlocation.x)
             xpos = max(xpos, paddle.size.width/2)
             xpos = min(xpos, size.width - paddle.size.width/2)
             paddle.position = CGPointMake(xpos, paddle.position.y)

         }

     }



     override func update(currentTime: CFTimeInterval) {

     } 
}

Answer 1

我无法看到你的代码中为paddle和ball创建了物理实体。所以，你实际上是在物理体存在之前尝试使用它们。这是一个工作示例，为您提供有关如何创建物理实体以及如何移动球拍的基本概念（您可以根据需要进行调整）：

//
//  GameScene.swift
//  gggame
//
//  Created by divy on 6/17/15.
//  Copyright (c) 2015 divy. All rights reserved.
//

import SpriteKit

class GameScene: SKScene , SKPhysicsContactDelegate {

    var istouchingpaddle = false
    let ballcat: UInt32 = 0x1 << 0
    let  ball = SKShapeNode(circleOfRadius: 20) //change this to create a ball from image, because using SKShapeNode can be inefficient 
    let paddle = SKSpriteNode(color: SKColor.grayColor(), size: CGSize(width: 100.0,height: 30.0))
    let paddlecat : UInt32 = 0x1 << 1

    override func didMoveToView(view: SKView) {

        self.physicsWorld.contactDelegate = self

        let border = SKPhysicsBody(edgeLoopFromRect: self.frame)
        border.friction = 0
        self.physicsBody = border

        //ball setting
        ball.name = "ball"

        ball.position = CGPoint(x: CGRectGetMidX(self.frame),y: CGRectGetMidY(self.frame))
        ball.physicsBody = SKPhysicsBody(circleOfRadius: ball.frame.size.width/2)
        ball.physicsBody?.allowsRotation = false
        ball.physicsBody?.affectedByGravity = true
        ball.physicsBody?.dynamic = true

        ball.physicsBody?.restitution = 1
        ball.physicsBody?.categoryBitMask = ballcat
        ball.physicsBody?.collisionBitMask = paddlecat
        ball.physicsBody?.contactTestBitMask = paddlecat


        paddle.name = "paddle"
        paddle.position = CGPoint(x: CGRectGetMidX(self.frame) ,y: CGRectGetMinY(self.frame)+100.0)
        paddle.physicsBody = SKPhysicsBody(rectangleOfSize: paddle.size)
        paddle.physicsBody?.allowsRotation = false
        paddle.physicsBody?.dynamic = false
        paddle.physicsBody?.affectedByGravity = false

        paddle.physicsBody?.restitution = 1

        paddle.physicsBody?.categoryBitMask = paddlecat
        paddle.physicsBody?.collisionBitMask = ballcat
        paddle.physicsBody?.contactTestBitMask = ballcat

        self.addChild(ball)
        self.addChild(paddle)

    }


    func didBeginContact(contact: SKPhysicsContact) {

    }

    override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {

        //touch setting

        var touch = touches.anyObject() as UITouch!
        var location = touch.locationInNode(self)
        if let body = self.physicsWorld.bodyAtPoint(location)

        {
            if body.node!.name == "paddle"
            {
                istouchingpaddle = true
            }

        }

    }

    override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
        istouchingpaddle = false
    }

    override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
        if istouchingpaddle{
            var touch = touches.anyObject() as UITouch!
            var currentlocation = touch.locationInNode(self)

            paddle.position = CGPointMake(currentlocation.x, paddle.position.y)

        }

    }

}