我在Swift中编写了这个简单的太空游戏，直到遇到碰撞检测问题为止。在浏览论坛，教程等之后，我尝试通过声明位掩码来实现冲突，如下所示：

对象1

    enemy?.physicsBody = SKPhysicsBody(circleOfRadius: ((enemy?.size.width)!/2))
    enemy?.physicsBody?.categoryBitMask = enemyBitMask
    enemy?.physicsBody?.contactTestBitMask = bulletBitMask
    enemy?.physicsBody?.collisionBitMask = 0

对象2

    bullet?.physicsBody? = SKPhysicsBody(rectangleOf: (bullet?.size)!)
    bullet?.physicsBody?.categoryBitMask =  bulletBitMask
    bullet?.physicsBody?.contactTestBitMask =  enemyBitMask
    bullet?.physicsBody?.collisionBitMask = 0
    bullet?.physicsBody?.usesPreciseCollisionDetection = true

我也将打印声明放在

func didBegin(_ contact: SKPhysicsContact) { print("Hello") }

这是我配置精灵的方法：

    func CreateNewEnemy() {
    var enemy : SKSpriteNode?

       let moveEnemyDown = SKAction.repeatForever(SKAction.moveBy(x: 0, y: -1, duration: 0.01))
       let rotateEnemy = SKAction.repeatForever(SKAction.rotate(byAngle: 25, duration: 5))

      let enemyXpos = randomNum(high:  self.frame.size.width/2, low: -1 * self.frame.size.width/2)
      let enemyYpos = randomNum(high:  2.5*self.frame.size.height, low: self.frame.size.height/2)
      let enemyOrigin : CGPoint = CGPoint(x: enemyXpos, y: enemyYpos)

      enemy = SKSpriteNode(imageNamed: possibleEnemyImage[Int(arc4random_uniform(4))])
      print(enemy?.size.height)
      enemy?.scale(to: CGSize(width: player.size.height, height: player.size.height))
      print(enemy?.size.height)
      enemy?.position = enemyOrigin
      enemy?.run(moveEnemyDown)
      enemy?.run(rotateEnemy)
      let enemyRadius : CGFloat = (enemy?.size.width)!/2
      print(enemyRadius)

      enemy?.physicsBody? = SKPhysicsBody(circleOfRadius: enemyRadius)

      enemy?.physicsBody?.categoryBitMask = enemyCategory
      enemy?.physicsBody?.contactTestBitMask = bulletCategory
      enemy?.physicsBody?.collisionBitMask = 0
      enemy?.zPosition = 1

      enemiesArray.append(enemy!)
      self.addChild(enemy!)
}

创造敌人（被召唤进入查看功能）

    func CreateAllEnemies(amountOfEnemies : UInt8) {
    for _ in 0...amountOfEnemies {
        CreateNewEnemy()
    }
}

和另一个精灵

    func CreateNewBullet() {
     let bulletOrigin : CGPoint = CGPoint(x: player.position.x, y: player.position.y+player.size.height/2)
     let moveBulletUp = SKAction.repeatForever(SKAction.moveBy(x: 0, y: 3, duration: 0.01))

     var bullet : SKSpriteNode?
     bullet = SKSpriteNode(imageNamed: "bulletImage")
     bullet?.position = bulletOrigin
     bullet?.run(moveBulletUp)

     bullet?.physicsBody? = SKPhysicsBody(rectangleOf: (bullet?.size)!)
     bullet?.physicsBody?.categoryBitMask =  bulletCategory
     bullet?.physicsBody?.contactTestBitMask = enemyCategory
     bullet?.physicsBody?.collisionBitMask = 0
     bullet?.physicsBody?.isDynamic = true
     bullet?.physicsBody?.usesPreciseCollisionDetection = true
     bullet?.zPosition = 1

     bulletsArray.append(bullet!)
     self.addChild(bullet!)
}

这个是用计时器创建的

bulletTimer = Timer.scheduledTimer(timeInterval: 0.25, target: self, selector: #selector(CreateNewBullet) , userInfo: nil, repeats: true)

不幸的是，当我看到两个对象接触后，它无法在控制台中打印任何内容。