Why my node calls didBeginContact method when its not in the Scene

问题

func didBeginContact(contact: SKPhysicsContact) {

        if contact.bodyA.categoryBitMask == PhysicsCategory.overPow || contact.bodyB.categoryBitMask == PhysicsCategory.overPow{
            let sk = delegateForCollision!.view as! SKView
            let newScene = GG(fileNamed: "GG")
            newScene!.delegateFor = delegateForCollision
            newScene?.scaleMode = .AspectFill
            sk.presentScene(newScene)
        }
        if contact.bodyA.categoryBitMask == PhysicsCategory.glem && contact.bodyB.categoryBitMask == PhysicsCategory.kappa{
            contact.bodyA.node?.removeFromParent()

            glem++
            glemLabel.text = "SKAŁY: \(glem)"

        }

        if contact.bodyB.categoryBitMask == PhysicsCategory.glem && contact.bodyA.categoryBitMask == PhysicsCategory.kappa{
            contact.bodyB.node?.removeFromParent()

            glem++
            glemLabel.text = "SKAŁY: \(glem)"
        }


    }

glem and kappa categoryBitMask nodes are colliding so glem variable should be ++ one time then node is removed from scene but it looks like this method is called more times during next frames. I see it in logs because I added print("\(glem)") in glem didSet. Why does it happen?

回答1:

I changed glem++ to if contact.bodyB.node?.parent != nil{glem++} and now it works as it should.

来源：https://stackoverflow.com/questions/34188183/why-my-node-calls-didbegincontact-method-when-its-not-in-the-scene