太多的敌人产卵，而不是与玩家碰撞

Question

所以我在上一个问题的@Fluidity的帮助下添加了这个最近的代码（以保持屏幕边框中的敌人节点），现在我的问题是，使用这个代码，太多的敌人正在倒下，他们＆＃ 39;不要像玩家之前那样与玩家射击的子弹或玩家节点本身发生碰撞。这是一些代码：

func createEnemy() {

    let wait:SKAction = SKAction.wait(forDuration: 1.25)
    //1.0 = 1.35
    let block:SKAction = SKAction.run(launchEnemy)

    let seq:SKAction = SKAction.sequence( [ wait, block ])

    let repeated:SKAction = SKAction.repeatForever(seq)

    self.run(repeated, withKey:"enemyLaunchAction")

    self.run(seq, withKey:"EnemySpawnAction") 
}

func launchEnemy() {

    let EnemyMissile:EnemyClass = EnemyClass()
    EnemyMissile.createEnemy("Enemy")
    addChild(EnemyMissile)

    let enemy = EnemyMissile.EnemyNode
    //  let randomX = arc4random_uniform( UInt32(screenWidth))

    var randomX = CGFloat(arc4random_uniform(UInt32(self.size.width))) // This is not a perfect rando algo.

    // Because our random x was from 0 through screenwidth, but .position works
    // on -halfWidth through +halfWidth
    randomX -= (self.frame.size.width / 2)

    // Because spawning on the border will mean that the enemy is HALF out of view:
    /*

     right border:       |
     enemy @ frame.maxX: x
     - offset:          x|
     - size.w/2        x |
     */
    enemy.position = CGPoint(  x: CGFloat(randomX)  - (screenWidth / 2), y: screenHeight + 50)

    let action = SKAction.move(by: CGVector(dx: 0, dy: -400 + speedScore), duration: 5.0)

    enemy.run(SKAction.repeatForever(action))

    increaseSpeed()

    print("enemy spawned!")

    self.run(action, withKey:"LaunchEnemyAction")
    let offset = CGFloat(5) // pixels, so enemy will have some spacing between borders.

    if randomX > self.frame.maxX - offset - (enemy.size.width / 2) {
        randomX = self.frame.maxX - offset - (enemy.size.width / 2)
    }
    else if randomX < self.frame.minX + offset + (enemy.size.width / 2) {
        randomX = self.frame.minX + offset + (enemy.size.width / 2)
    }

    enemy.position.x = randomX
}

func keepEnemyInBounds() {
    // A better way to do this would be to have a dictionary of enemies:
    for node in self.children {
        guard node.name == "enemy" else { continue }
        let enemy = node as! SKSpriteNode

        if enemy.position.x > frame.maxX - (enemy.size.width / 2) {
            enemy.position.x = frame.maxX - (enemy.size.width / 2)
        }
        else if enemy.position.x < frame.minX + (enemy.size.width / 2) {
            enemy.position.x = frame.minX + (enemy.size.width / 2)
        }
    }
}

override func update(_ currentTime: TimeInterval) {
    launchEnemy()
}
override func didFinishUpdate() {
    keepEnemyInBounds()
}

联络听证代码：

   func didBegin(_ contact: SKPhysicsContact) {

      _ = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask

      if (contact.bodyA.categoryBitMask == BodyType.enemy.rawValue && contact.bodyB.categoryBitMask == BodyType.bullet.rawValue)    {

          if let missile = contact.bodyA.node! as? EnemyClass {

               enemyMissileAndBullet(missile)         
          }

          contact.bodyB.node?.name = "removeNode"

      } else if ( contact.bodyA.categoryBitMask == BodyType.bullet.rawValue && contact.bodyB.categoryBitMask == BodyType.enemy.rawValue) {

          if let missile = contact.bodyB.node! as? EnemyClass {
                  enemyMissileAndBullet(missile)
          }

          contact.bodyA.node?.name = "removeNode"
      }

      if ( contact.bodyA.categoryBitMask == BodyType.player.rawValue && contact.bodyB.categoryBitMask == BodyType.enemy.rawValue) {

        createExplosion(contact.bodyB.node!.position , image:"explosion2")

        contact.bodyB.node?.name = "removeNode"

        updateScore(1)

        subtractHealth()

        playSound("shipExplosion")

       } else if (contact.bodyA.categoryBitMask == BodyType.enemy.rawValue && contact.bodyB.categoryBitMask == BodyType.player.rawValue) {

           createExplosion(contact.bodyA.node!.position , image:"explosion2")

           contact.bodyA.node?.name = "removeNode"

           updateScore(1)

           subtractHealth()

           playSound("shipExplosion")
      }
}

编辑：

联系人监听器已清理：需要播放器＆lt; missle＆lt;敌人

  func didBegin(_ contact: SKPhysicsContact) {
      let bodyA = contact.bodyA.categoryBitMask >= contact.bodyA.categoryBitMask ? contact.bodyA : contact.bodyB
      let bodyB = contact.bodyA.categoryBitMask < contact.bodyA.categoryBitMask ? contact.bodyA : contact.bodyB
      if contact.bodyA.categoryBitMask == BodyType.bullet.rawValue && contact.bodyB.categoryBitMask == BodyType.enemy.rawValue    {

          if let missile = contact.bodyA.node! as? EnemyClass {
               enemyMissileAndBullet(missile)         
          }

          contact.bodyB.node?.name = "removeNode"

      } 
      else if contact.bodyA.categoryBitMask == BodyType.player.rawValue && contact.bodyB.categoryBitMask == BodyType.enemy.rawValue {

        createExplosion(bodyB.node!.position , image:"explosion2")
        bodyB.node?.name = "removeNode"
        updateScore(1)
        subtractHealth()
        playSound("shipExplosion")
       } 
  }