swift - 如何创建子类对象？

Question

不幸的是，我的代码一次又一次地收到错误消息 'self' used in property access 'healthPoints before 'super.init' call:

头等舱单元

import UIKit
import SpriteKit

class Unit {

//    var gameScene : GameScene!

    var healthPoints = 10
    var damage = 5
    var movement = 1

    init(pHealthPoints: Int, pDamage: Int,pMovement: Int) {

        self.healthPoints = pHealthPoints
        self.damage = pDamage
         self.movement = pMovement
    }


    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

子类骑士

import UIKit
import SpriteKit

class Knight: Unit {

    override init(pHealthPoints: Int, pDamage: Int, pMovement: Int) {

        self.healthPoints = pHealthPoints
        self.damage = pDamage
        self.movement = pMovement

    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

super 到底应该写在子类的什么地方？

如何通过 GameScene.swift 访问类 Unit 或类 Knight 或创建对象 属于 Knight 类？

对于每一个回答我都非常感激

Answer 1

您只需调用 super.init 即可为子类的属性赋值。也不需要实现 init?(coder aDecoder: NSCoder)。另请记住，您重写的 init 方法实际上与 super 实现没有任何不同，因此重写它没有意义。

class Knight: Unit {

    override init(pHealthPoints: Int, pDamage: Int, pMovement: Int) {
        super.init(pHealthPoints: pHealthPoints, pDamage: pDamage, pMovement: pMovement)
        self.healthPoints = pHealthPoints
        self.damage = pDamage
        self.movement = pMovement
    }
}