Swift

下面通过一个样例演示如何实现飞行道具的生成，以及道具碰撞拾取。

样例说明：

1，屏幕从右到左不断地生成苹果飞过来（苹果高度随机）

2，点击屏幕可以让熊猫跳跃

3，熊猫碰到苹果，苹果消失

运行效果：

样例代码：

苹果工厂类 AppleFactory.swift

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import SpriteKit   class AppleFactory:SKNode{     //定义苹果纹理     let appleTexture = SKTexture(imageNamed: "apple")     //游戏场景的狂赌     var sceneWidth :CGFloat = 0.0     //定义苹果数组     var arrApple = [SKSpriteNode]()     //定时器     var timer = NSTimer()           func onInit(CGFloat) {         self.sceneWidth = width         //启动的定时器         timer = NSTimer.scheduledTimerWithTimeInterval( 0.2, target: self,             selector: "createApple", userInfo: nil, repeats: true)     }           //创建苹果类     func createApple(){         //通过随机数来随机生成苹果         //算法是，随机生成0-9的数，当随机数大于8的时候声称苹果         //也就是说，有1/10的几率生成苹果         //这样游戏场景中的苹果就不会整整齐齐以相同间隔出现了         let random = arc4random() % 10         if random > 8 {             //生成苹果             let apple = SKSpriteNode(texture: appleTexture)             //设置物理体             apple.physicsBody = SKPhysicsBody(rectangleOfSize: apple.size)             //弹性设为0             apple.physicsBody?.restitution = 0             //物理体标识             apple.physicsBody?.categoryBitMask = BitMaskType.apple             //不受物理效果影响             apple.physicsBody?.dynamic = false             //设置中心点             apple.anchorPoint = CGPointMake(0, 0)             //z轴深度             apple.zPosition = 40             //设定位置             let theY = CGFloat(arc4random()%200 + 200)             apple.position  = CGPointMake(sceneWidth+apple.frame.width , theY)             //加入数组             arrApple.append(apple)             //加入场景             self.addChild(apple)         }     }           //苹果移动方法     func move(speed:CGFloat){         for apple in arrApple {             apple.position.x -= speed         }         //移出屏幕外时移除苹果         if arrApple.count > 0 && arrApple[0].position.x < -20{             arrApple[0].removeFromParent()             arrApple.removeAtIndex(0)         }     }           //重置方法     func reSet(){         //移除所有子对象         self.removeAllChildren()         //清空苹果数组         arrApple.removeAll(keepCapacity: false)     } }

熊猫类 Panda.swift

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import SpriteKit   class Panda: SKSpriteNode {     //定义纹理     let pandaTexture = SKTexture(imageNamed: "panda")           init() {         //执行父类的构造方法         super.init(texture:pandaTexture,color:SKColor.whiteColor(),size:pandaTexture.size())         //设置中心点         self.anchorPoint = CGPointMake(0, 0)                   self.physicsBody = SKPhysicsBody(rectangleOfSize:pandaTexture.size())         self.physicsBody?.dynamic = true         self.physicsBody?.allowsRotation = false                   //弹性         self.physicsBody?.restitution = 0         self.physicsBody?.categoryBitMask = BitMaskType.panda         self.physicsBody?.contactTestBitMask = BitMaskType.scene|BitMaskType.apple         self.physicsBody?.collisionBitMask = BitMaskType.scene     }           required init(coder aDecoder: NSCoder) {         fatalError("init(coder:) has not been implemented")     }           //跳     func jump (){         //施加一个向上的力，让小人跳起来         self.physicsBody?.velocity = CGVectorMake(0, 700)     } }

碰撞标识类 - BitMaskType.swift

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class BitMaskType {     class var panda:UInt32{         return 1<<0     }     class var apple:UInt32{         return 1<<1     }     class var scene:UInt32{         return 1<<2     } }

主场景 - GameScene.swift

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import SpriteKit   class GameScene: SKScene,SKPhysicsContactDelegate {     lazy var appleFactory = AppleFactory()     lazy var panda = Panda()           //移动速度     var moveSpeed:CGFloat = 15     //吃到的苹果数     var appleNum = 0           override func didMoveToView(view: SKView) {         //物理世界代理         self.physicsWorld.contactDelegate = self         //重力设置         self.physicsWorld.gravity = CGVectorMake(0, -5)         //设置物理体         self.physicsBody = SKPhysicsBody(edgeLoopFromRect: self.frame)         //设置种类标示         self.physicsBody?.categoryBitMask = BitMaskType.scene         //是否响应物理效果         self.physicsBody?.dynamic = false                   //场景的背景颜色         let skyColor = SKColor(red:113/255,green:197/255,blue:207/255,alpha:1)         self.backgroundColor = skyColor                   //给小人定一个初始位置         panda.position = CGPointMake(200, 400)         //将小人显示在场景中         self.addChild(panda)                   //苹果工厂         appleFactory.onInit(self.frame.width)         self.addChild( appleFactory )     }           override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {         panda.jump()     }          override func update(currentTime: CFTimeInterval) {         appleFactory.move(moveSpeed)     }           //碰撞检测方法     func didBeginContact(contact: SKPhysicsContact) {         //熊猫和苹果碰撞         if (contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask)             == (BitMaskType.apple | BitMaskType.panda){                 //苹果计数加1                 self.appleNum++                 //如果碰撞体A是苹果，隐藏碰撞体A，反之隐藏碰撞体B                 //（因为苹果出了屏幕都会被移除，所以这里隐藏就可以了）                 if contact.bodyA.categoryBitMask == BitMaskType.apple {                     contact.bodyA.node?.hidden = true                 }else{                     contact.bodyB.node?.hidden = true                 }         }     } }

源码下载：EatApple.zip