Swift - Must call a designated initializer of the superclass SKSpriteNode error

问题:

This code worked on first XCode 6 Beta, but on latest Beta it's not working and gives such errors Must call a designated initializer of the superclass SKSpriteNode:

import SpriteKit  class Creature: SKSpriteNode {   var isAlive:Bool = false {     didSet {         self.hidden = !isAlive     }   }   var livingNeighbours:Int = 0    init() {     // throws: must call a designated initializer of the superclass SKSpriteNode     super.init(imageNamed:"bubble")      self.hidden = true   }    init(texture: SKTexture!) {     // throws: must call a designated initializer of the superclass SKSpriteNode     super.init(texture: texture)   }    init(texture: SKTexture!, color: UIColor!, size: CGSize) {     super.init(texture: texture, color: color, size: size)   } } 

and that's how this class is initialiazed:

let creature = Creature() creature.anchorPoint = CGPoint(x: 0, y: 0) creature.position = CGPoint(x: Int(posX), y: Int(posY)) self.addChild(creature) 

I'm stuck with it.. what will be the easiest fix?

回答1:

init(texture: SKTexture!, color: UIColor!, size: CGSize) is the only designated initializer in the SKSpriteNode class, the rest are all convenience initializers, so you can't call super on them. Change your code to this:

class Creature: SKSpriteNode {     var isAlive:Bool = false {         didSet {             self.hidden = !isAlive         }     }     var livingNeighbours:Int = 0      init() {         // super.init(imageNamed:"bubble") You can't do this because you are not calling a designated initializer.         let texture = SKTexture(imageNamed: "bubble")         super.init(texture: texture, color: UIColor.clearColor(), size: texture.size())         self.hidden = true     }      init(texture: SKTexture!) {         //super.init(texture: texture) You can't do this because you are not calling a designated initializer.         super.init(texture: texture, color: UIColor.clearColor(), size: texture.size())     }      init(texture: SKTexture!, color: UIColor!, size: CGSize) {         super.init(texture: texture, color: color, size: size)     } } 

Furthermore I would consolidate all of these into a single initializer.

回答2:

Crazy stuff.. I'm not fully understand how I managed to fix it.. but this works:

convenience init() {     self.init(imageNamed:"bubble")     self.hidden = true }  init(texture: SKTexture!, color: UIColor!, size: CGSize) {     super.init(texture: texture, color: color, size: size) } 

add convenience to init and remove init(texture: SKTexture!)

文章来源: Swift - Must call a designated initializer of the superclass SKSpriteNode error