我实现了一个带有附加属性的类SKSpriteNode的子类。然后,我创建了它的一个实例,并尝试在每个帧中修改其属性的值,但是遇到错误。
有什么办法可以解决这个问题?
import SpriteKit
import GameplayKit
class SomeSprite: SKSpriteNode {
var direction: CGVector = CGVector(dx: 0, dy: 0)
convenience init() {
self.init(imageNamed: "imgSprite")
}
}
class GameScene: SKScene {
override func didMove(to view: SKView) {
//Create a sprite instance
var sampleSprite = SomeSprite()
sampleSprite.name = "Sprite"
sampleSprite.zPosition = 1
sampleSprite.position = CGPoint(x: 100, y: 100)
sampleSprite.direction = CGVector(dx: 10, dy: 10)
sampleSprite.setScale(1)
self.addChild(sampleSprite)
}
override func update(_ currentTime: TimeInterval) {
//Calculate before rendering frame
self.enumerateChildNodes(withName: "Sprite") { (sprite, stop) in
sprite.position = CGPoint(x: 150, y: 150) //This works properly
sprite.direction = CGVector(dx: 15, dy: 15) //Error: Value of type SKNode has no member 'direction'
}
}
}
最佳答案
方法enumerateChildNodes 返回SKNode列表
您必须尝试将对象强制转换为类 SomeSprite
override func update(_ currentTime: TimeInterval) {
//Calculate before rendering frame
self.enumerateChildNodes(withName: "Sprite") { (sprite, stop) in
sprite.position = CGPoint(x: 150, y: 150) //This works properly
if let someSprite = sprite as? SomeSprite {
someSprite.direction = CGVector(dx: 15, dy: 15)
}
}
}
关于ios - 寻找每帧更新实例属性的方法,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/60632490/