从 Sprites UserData 保存和读取信息

Question

我正在尝试将一个值保存到精灵的用户数据中并能够读取它。

这就是我所拥有的，由于某种原因，该值永远不会被保存并保持为零。

import SpriteKit

let frame = SKScene()

func createSprite() {
    let sprite = SKSpriteNode()
    sprite.userData?.setValue("100", forKeyPath: "key")
    frame.addChild(sprite)
}

createSprite()

for child in frame.children where child is SKSpriteNode {
    print(child.userData?.valueForKey("key") as? String)
    //prints the value saved in the childs user data

    if child.userData?.valueForKey("key") as? String == "100" {
        print("It was a Success!")
    }
    if child.userData?.valueForKey("key") as? String == nil {
        print("There was a problem :(")
    }
}

Answer 1

我相信您的问题是 userData 以 nil 开头。试试这个...

func createSprite() {
    let sprite = SKSpriteNode()
    //init NSMutableDictionary
    sprite.userData = NSMutableDictionary()
    sprite.userData?.setValue("100", forKeyPath: "key")
    frame.addChild(sprite)
}

希望对您有所帮助。