c# - 由 C# 参数通过引用而不是值传递引起的动画问题，但是在哪里？

Question

我在 XNA 中遇到 Sprite 动画问题，这似乎是由作为引用值传递的结构引起的。但我没有在任何地方使用 ref 关键字。诚然，我是一个 C# 菜鸟，所以这里可能有一些浅薄的愚蠢错误，但我看不到。

我正在创建 10 只 Ant 或蜜蜂，并在它们在屏幕上移动时制作动画。我有一个动画结构数组，每次我创建一只 Ant 或蜜蜂时，我都会向它发送它需要的动画数组值(此时只是 [0] 或 [1])。动画结构的深处是一个用于更改帧的计时器。 ant/bee 类将动画结构存储为私有(private)变量。

我看到的是每只 Ant 或蜜蜂都使用相同的动画结构，我认为我正在传入并按值复制的那个。因此，在 Update() 期间，当我为每只 Ant /蜜蜂提前动画计时器时，下一只 Ant /蜜蜂的动画计时器会提前一小段时间。如果屏幕上有 1 只 Ant ，它会正确地设置动画。 2只 Ant ，它跑得快一倍，以此类推。显然，这不是我想要的。

这是代码的简化版本。 BerryPicking 的 ActorAnimationGroupData[] 如何在 BerryCreatures 之间共享？

class BerryPicking
{
    private ActorAnimationGroupData[] animations;
    private BerryCreature[] creatures;
    private Dictionary<string, Texture2D> creatureTextures;
    private const int maxCreatures = 5;

    public BerryPickingExample()
    {
        this.creatures = new BerryCreature[maxCreatures];
        this.creatureTextures = new Dictionary<string, Texture2D>();
    }

    public void LoadContent()
    {
        // Returns data from an XML file
        Reader reader = new Reader();
        animations = reader.LoadAnimations();

        CreateCreatures();
    }

    // This is called from another function I'm not including because it's not relevant to the problem.
    // In it, I remove any creature that passes outside the viewport by setting its creatures[] spot to null.
    // Hence the if(creatures[i] == null) test is used to recreate "dead" creatures. Inelegant, I know.
    private void CreateCreatures()
    {
        for (int i = 0; i < creatures.Length; i++)
        {
            if (creatures[i] == null)
            {
                // In reality, the name selection is randomized
                creatures[i] = new BerryCreature("ant");

                // Load content and texture (which I create elsewhere)
                creatures[i].LoadContent(
                    FindAnimation(creatures[i].Name),
                    creatureTextures[creatures[i].Name]);
            }
        }
    }

    private ActorAnimationGroupData FindAnimation(string animationName)
    {
        int yourAnimation = -1;

        for (int i = 0; i < animations.Length; i++)
        {
            if (animations[i].name == animationName)
            {
                yourAnimation = i;
                break;
            }
        }

        return animations[yourAnimation];
    }

    public void Update(GameTime gameTime)
    {
        for (int i = 0; i < creatures.Length; i++)
        {
            creatures[i].Update(gameTime);
        }
    }
}

class Reader
{
    public ActorAnimationGroupData[] LoadAnimations()
    {
        ActorAnimationGroupData[] animationGroup;
        XmlReader file = new XmlTextReader(filename);

        // Do loading...

        // Then later
        file.Close();
        return animationGroup;
    }
}

class BerryCreature
{
    private ActorAnimation animation;
    private string name;

    public BerryCreature(string name)
    {
        this.name = name;
    }

    public void LoadContent(ActorAnimationGroupData animationData, Texture2D sprite)
    {
        animation = new ActorAnimation(animationData);
        animation.LoadContent(sprite);
    }

    public void Update(GameTime gameTime)
    {
        animation.Update(gameTime);
    }
}

class ActorAnimation
{
    private ActorAnimationGroupData animation;

    public ActorAnimation(ActorAnimationGroupData animation)
    {
        this.animation = animation;
    }

    public void LoadContent(Texture2D sprite)
    {
        this.sprite = sprite;
    }

    public void Update(GameTime gameTime)
    {
        animation.Update(gameTime);
    }
}

struct ActorAnimationGroupData
{
    // There are lots of other members of this struct, but the timer is the only one I'm worried about.
    // TimerData is another struct
    private TimerData timer;

    public ActorAnimationGroupData()
    {
        timer = new TimerData(2);
    }

    public void Update(GameTime gameTime)
    {
        timer.Update(gameTime);
    }
}

struct TimerData
{
    public float currentTime;
    public float maxTime;

    public TimerData(float maxTime)
    {
        this.currentTime = 0;
        this.maxTime = maxTime;
    }

    public void Update(GameTime gameTime)
    {
        currentTime += (float)gameTime.ElapsedGameTime.TotalSeconds;
        if (currentTime >= maxTime)
        {
            currentTime = maxTime;
        }
    }
}

Answer 1

您确定每个生物都使用了新的 ActorAnimation 吗？我将创建一个包含两个生物的测试，并为每个生物的 animation.animation 值设置监视，并逐步执行更新以查看它们何时发生变化。您的 Updates() 是否可能被多次调用？