Swift Spritekit在呈现新场景后自行调整图像大小

我在基本SpriteKit模板的第一个屏幕中添加了一个精灵。但是，无论何时我进入播放场景并返回到菜单场景，图像都会放大。在检查大小和缩放模式后，一切似乎都正常。我不确定为什么会发生这种情况。Swift Spritekit在呈现新场景后自行调整图像大小

这是菜单代码：

enter image description here

这是从一个场景返回菜单代码：移动到下一个场景前

let playButton = SKSpriteNode(imageNamed: "play") 


override func didMoveToView(view: SKView) 
{ 
    /* Setup your scene here */ 

    //Place button in exact middle of the screen 
    self.playButton.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame)) 

    addChild(self.playButton) 

    self.backgroundColor = UIColor.blueColor() 

} 

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) 
{ 
    /* Called when a touch begins */ 

    for touch: AnyObject in touches 
    { 
     let location = touch.locationInNode(self) 

     if self.nodeAtPoint(location) == self.playButton 
     { 
      var scene = PlayJumper() 
      let sKView = self.view as SKView! 
      sKView.ignoresSiblingOrder = true 
      scene.scaleMode = .AspectFill 
      scene.size = sKView.bounds.size 

      sKView.presentScene(scene) 
     } 

    } 
}

场景截图，以及返回到屏幕后更改的图像。

import SpriteKit 

class PlayJumper : SKScene 
{ 


override func didMoveToView(view: SKView){ 
    self.backgroundColor = UIColor.orangeColor() 
} 

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) 
{ 
    for touch: AnyObject in touches 
    { 
     endGame() 
    } 
} 

func endGame() 
{ 
    if let scene = GameScene.unarchiveFromFile("GameScene") as? GameScene 
    { 
     let sKView = self.view as SKView! 
     sKView.ignoresSiblingOrder = true 
     scene.size = sKView.bounds.size 
     scene.scaleMode = .AspectFill 
     sKView.presentScene(scene) 
    } 
} 

}

这是回到视图后的图像，它比以前的图像稍大。

enter image description here