Swift SpriteKit：应该将节点从父节点移除时

Question

I have a game (like Doodle Jump) where my player hits objects and bounces off of them to advance and gain points. As the player hits said objects, they should just disappear (.removeFromParent()) as it is called in a function in GameScene and in its own separate class. Can anyone tell me what Im doing wrong?

Here is my code for GameScene:

 func createSnowAtPosition(position: CGPoint) -> SKNode {
  var sprite: SKSpriteNode!
   sprite = SKSpriteNode(imageNamed: "icons_winter_09")


    let node = Snowflake()
    let position = CGPoint(x: position.x, y: position.y)
    node.position = position
    node.name = "SNOW"

    node.addChild(sprite)
    sprite.physicsBody?.affectedByGravity = false
    sprite.physicsBody?.categoryBitMask = snowCategory
    sprite.physicsBody?.collisionBitMask = playerCategory
    sprite.physicsBody = SKPhysicsBody(circleOfRadius: snow.size.width / 7)
    sprite.physicsBody?.dynamic = false
    return node



}
  func didBeginContact(contact: SKPhysicsContact) {


    if player.physicsBody?.velocity.dy < 0 {
        // 2
        player.physicsBody?.velocity = CGVector(dx: player.physicsBody!.velocity.dx, dy: 250.0)
        // Play sound
        runAction(starSound) {
         snow.removeFromParent()
        }
        if snow.position.y < player.position.y {
            let pointsLabel = childNodeWithName("scoreLabel") as! Points
            pointsLabel.increment()
        }

        }

And here is my code for the separate class:

  import Foundation
   import SpriteKit
 let snow = SKSpriteNode(imageNamed: "icons_winter_09")
    class Snowflake: SKSpriteNode {

init() {
    let size = CGSizeMake(40, 50)
  super.init(texture: nil, color: UIColor.clearColor(), size: size)




   }

  required init?(coder aDecoder: NSCoder) {
     fatalError("init(coder:) has not been implemented")
  }

   func loadBodyWithSize(size: CGSize) {

    snow.physicsBody?.affectedByGravity = false
    snow.physicsBody?.categoryBitMask = snowCategory
    snow.physicsBody?.collisionBitMask = playerCategory
     snow.physicsBody = SKPhysicsBody(circleOfRadius: snow.size.width / 3)

   }

   func createSnowsAtPosition() {
   snow.name = "snow"
    snow.position =  CGPointMake(50, 200)

    snow.physicsBody?.dynamic = false
    snow.physicsBody?.usesPreciseCollisionDetection = true
    addChild(snow)


     }

    }

Answer 1

Define the physics body before you start settings its properties, also don't add the node until the physics body is defined, so:

let node = Snowflake()
let position = CGPoint(x: position.x, y: position.y)
node.position = position
node.name = "SNOW"l
sprite.physicsBody?.affectedByGravity = false
sprite.physicsBody?.categoryBitMask = snowCategory
sprite.physicsBody?.collisionBitMask = playerCategory
sprite.physicsBody = SKPhysicsBody(circleOfRadius: snow.size.width / 7)
sprite.physicsBody?.dynamic = false
addNode(node)
return node