Question

我正在制作纸牌游戏，我有几个控制卡片行为的脚本。

public class BasicCardModel : Draggable {
    public int hitPoints;
    public GameObject cardObject;
    public static string cardName = "Basic Card";

    public CardStatus cardStatus = CardStatus.None;

    public void copyAttributes(BasicCardModel bcm) {
        Debug.Log("Calling basic copy attributes");
        hitPoints = bcm.hitPoints;
    }
    ...
}

我有几张类似下面的专用卡片：

public class AttackCardModel : BasicCardModel {
    public int attackStrength;
    public AttackType attackType;

    public void copyAttributes(AttackCardModel acm) {
        base.copyAttributes(acm);
        attackType = acm.attackType;
        Debug.Log("Attack strength = " + acm.attackStrength);
        attackStrength = acm.attackStrength;
    }
}

我有一个生成这些卡的控制器对象：

public class GameController : MonoBehaviour {
    public GameObject basicCard, attackCard, defenseCard, eventCard, masterCard;
    public GameObject topPlayerDeck, topPlayerHand, topPlayerField;
    public GameObject bottomPlayerDeck, bottomPlayerHand, bottomPlayerField;
    public GameObject eventDeck;
    // Use this for initialization
    void Start () {
        // Link controller to game objects
        topPlayerDeck = GameObject.Find("TopPlayerDeck");
        topPlayerHand = GameObject.Find("TopPlayerHand");
        topPlayerField = GameObject.Find("TopPlayerField");
        bottomPlayerDeck = GameObject.Find("BottomPlayerDeck");
        bottomPlayerHand = GameObject.Find("BottomPlayerHand");
        bottomPlayerField = GameObject.Find("BottomPlayerField");
        eventDeck = GameObject.Find("EventDeck");

        CardCollection cards = generateCards();

        foreach (BasicCardModel card in cards.cards) {
            if(card is AttackCardModel) {
                createCard<AttackCardModel>(topPlayerHand, card as AttackCardModel, Player.Top, CardStatus.Hand);
                createCard<AttackCardModel>(bottomPlayerHand, card as AttackCardModel, Player.Bottom, CardStatus.Hand);
            }
            else if(card is DefenseCardModel) {
                createCard<DefenseCardModel>(topPlayerHand, card as DefenseCardModel, Player.Top, CardStatus.Hand);
                createCard<DefenseCardModel>(bottomPlayerHand, card as DefenseCardModel, Player.Bottom, CardStatus.Hand);
            }
            else {
                createCard<BasicCardModel>(topPlayerHand, card as BasicCardModel, Player.Top, CardStatus.Hand);
                createCard<BasicCardModel>(bottomPlayerHand, card as BasicCardModel, Player.Bottom, CardStatus.Hand);
            }
        }

        /*
        for(int i = 0; i < 2; i++) {
            createCard<AttackCardModel>(topPlayerHand, Player.Top, CardStatus.Hand);
            createCard<AttackCardModel>(bottomPlayerHand, Player.Bottom, CardStatus.Hand);
        }
        for (int i = 0; i < 2; i++) {
            createCard<DefenseCardModel>(topPlayerHand, Player.Top, CardStatus.Hand);
            createCard<DefenseCardModel>(bottomPlayerHand, Player.Bottom, CardStatus.Hand);
        }
        */
    }

    // Update is called once per frame
    void Update () {

    }

    // For testing, have a CardCollection passed in later
    public CardCollection generateCards() {
        CardCollection cards = new CardCollection();
        //AttackCardModel testcard = new AttackCardModel(4, AttackType.SQLInjection, 3);
        cards.cards.Add(new AttackCardModel(4, AttackType.SQLInjection, 3));
        cards.cards.Add(new DefenseCardModel(5, AttackType.SQLInjection, 1));
        //Debug.Log(testcard.attackStrength + "is attack strength");
        return cards;
    }

    public void createCard<T>(GameObject whereToPut, T objectToCopy, Player player, CardStatus cardStatus) where T : BasicCardModel {
        GameObject new_card = Instantiate(basicCard);
        new_card.transform.SetParent(whereToPut.transform, false);
        Destroy(new_card.GetComponent<BasicCardModel>());
        new_card.AddComponent<T>();
        --->new_card.GetComponent<T>().copyAttributes(objectToCopy); <---
        new_card.GetComponent<T>().linkModelToCardObject(new_card);
        new_card.GetComponent<T>().setUpCard<T>(player, cardStatus);
    }
}

我在使用此行时遇到问题（靠近控制器对象的末尾）： new_card.GetComponent<T>().copyAttributes(objectToCopy);

它不调用copyAttributes的子方法，而是调用父方法，因此不会复制我想要的属性。

在我之前的一个问题中，有人建议使用动态类型作为解决方案。但是，即使GetComponent<ParentClass>应该获得子类型，但由于某种原因它不起作用，所以我需要使用泛型。

如何强制它调用子方法而不是父方法？

Answer 1

将BasicCardModel的{{1}}方法设为虚拟。

copyAttributes

然后覆盖它public class BasicCardModel : Draggable { // ... public virtual void copyAttributes(BasicCardModel bcm) { // ... } // ... }，并在复制其他属性之前将卡模型转换为派生类型：

AttackCardModel

Answer 2

您需要在类型中反映层次结构 - 一种方法是在Create方法中创建界面并为其添加约束：

public interface ICopyableFrom<T>
{
     void CopyAttributes(T src);
}

public void createCard<T>(GameObject whereToPut, T objectToCopy, Player player, CardStatus cardStatus) where T : BasicCardModel, ICopyableFrom<T>
{
        GameObject new_card = Instantiate(basicCard);
        new_card.transform.SetParent(whereToPut.transform, false);
        Destroy(new_card.GetComponent<BasicCardModel>());
        new_card.AddComponent<T>();
        new_card.GetComponent<T>().CopyAttributes(objectToCopy);
        new_card.GetComponent<T>().linkModelToCardObject(new_card);
        new_card.GetComponent<T>().setUpCard<T>(player, cardStatus);
}

然后你需要在你的课程中实现：

public class AttackCardModel : BasicCardModel, ICopyableFrom<AttackCardModel>
{
    public void CopyAttributes(AttackCardModel src)
    {
    }
}

使用Child类型作为参数的方法的继承类：调用错误的方法

2 个答案: