Swift SpriteKit：应该将节点从父节点移除时

Question

我有一个游戏（例如Doodle Jump），我的玩家击中了物体并从物体上反弹来前进并获得积分。 当玩家击中这些对象时，它们应该消失（.removeFromParent（）），因为它们在GameScene中的函数中以及在其自己的单独类中被调用。 谁能告诉我我做错了什么？

这是我的GameScene代码：

 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()
        }

        }

这是我为单独的类编写的代码：

  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

在开始设置其物理属性之前，先定义该物理体，也不要在定义该物理体之前添加节点，因此：

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