c# - 如何在 XML 中保存对象实例的引用

Question

编辑:得到了答案，我将播放器中的列表 Inv 更改为一个 int 列表，并将游戏初始加载时的项目导入字典中，如下所示:

public static class InitLoad
{
    static List<ItemEquipmentWeapon> weapons;

    public static Dictionary<int, Item> ItemIDList = new Dictionary<int, Item>();

    public static void PreLoading()
    {

        string path, filePath, 
            weaponFile = @"\WeaponsItem.aid";
        XmlSerializer SerializerObj;
        FileStream ReadFileStream;

        path = string.Format(@"{0}\AwesomeRPG\Data\Items",
            Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData));
        filePath = string.Format(@"{0}\{1}", path, weaponFile);
        SerializerObj = new XmlSerializer(typeof(ItemEquipmentWeapon));
        ReadFileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
        weapons = (List<ItemEquipmentWeapon>)SerializerObj.Deserialize(ReadFileStream);
        foreach (Item item in weapons)
        {
            ItemIDList.Add(item.ID, item);
        }
    }
}

这意味着我可以用我的播放器类来做到这一点:

[Serializable()]
public class Player : Entity
{
    public string Name { get; set; }
    public int MaxHP { get; set; }
    public int Level { get; set; }
    public int XP { get; set; }
    public int Str { get; set; }
    public int End { get; set; }
    public int Dex { get; set; }
    public int Agi { get; set; }
    public int Wis { get; set; }
    public int Int { get; set; }
    //Create a list of Item Id's for inventory
    public List<int> Inv { get; set; }

    private int lHand;
    private int rHand;

    public int LHand
    {
        get 
        { return lHand; }
        set
        {
            if (!value.THand)
            {
                lHand = value;
            }
            else lHand = null;
        }
    }
    public int RHand
    {
        get 
        { return rHand; }
        set 
        { rHand = value; }
    }

    internal Player() { }
    public Player(string name, int maxhp, int hp, int lvl, int exp, int str, int end, int dex, int agi, int wis, int inte)
        : base(true, hp)
    {
        Name = name;
        MaxHP = maxhp;
        Level = lvl;
        XP = exp;
        Str = str;
        End = end;
        Dex = dex;
        Agi = agi;
        Wis = wis;
        Int = inte;

        Inv = new List<int>();
    }

    public List<string> GetInv()
    {
        List<string> val = new List<string>();
        Item item;
        foreach (int i in Inv)
        {
            InitLoad.ItemIDList.TryGetValue(i, out item);
            val.Add(item.Name);
        }

        return val;
    }

    public void AddItem(Item i, int amt)
    {
        for (int j = 0; j < amt; j++)
        {
            Inv.Add(i.ID);
        }
    }
    public void AddItem(Item i){
        AddItem(i, 1); }

    public void RemoveItem(Item i, int amt)
    {
        int count = 0;

        foreach (int item in Inv)
        {
            if (item == i.ID)
            {
                Inv.Remove(item);
                count++;
            }
            if (count == amt)
            {
                break;
            }
        }
    }
    public void RemoveItem(Item i){
        RemoveItem(i, 1); }

    public bool HasItem(Item i, int amt)
    {
        int count = 0;

        foreach (int item in Inv)
        {
            if (item == i.ID)
            {
                count++;
            }
        }

        return count >= amt;
    }
    public bool HasItem(Item i){
        return HasItem(i, 1); }
}

希望这对其他人有帮助!

原始问题:

因此，我正在制作一个带有 Windows 窗体的愚蠢的小型 RPG 游戏来测试我的技能，并且我正在整理保存。目前它保存到一个 XML 文件，该文件是一个自定义扩展名 (.asd)这是我的保存/加载代码:

public static class SaveGame
{
    public static void Save(Player player)
    {
        string myfile = string.Format(@"{1}\AwesomeRPG\Saves\{0}Save.asd", player.Name, Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData));
        //Delete file if it already exists
        if (File.Exists(myfile)) System.IO.File.Delete(myfile);
        //Create/Write to the file
        FileStream outFile = File.Create(myfile);            
        XmlSerializer Serializer = new XmlSerializer(typeof(Player));
        Serializer.Serialize(outFile, player);
        outFile.Close();
    }

    public static Player Load(string FileName)
    {
        string myfile = string.Format(@"{1}\AwesomeRPG\Saves\{0}Save.asd", FileName, Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData));

        if (!File.Exists(myfile)) return null;
        XmlSerializer Serializer = new XmlSerializer(typeof(Player));
        FileStream ReadFileStream = new FileStream(myfile, FileMode.Open, FileAccess.Read, FileShare.Read);
        return (Player)Serializer.Deserialize(ReadFileStream);
    }
}

如您所想，这将保存 Inv 列表中任何项目的所有详细信息。但是，我希望在游戏开始时加载所有存在的项目(创建它们的实例)，并且我需要一种方法让保存文件保存对这些实例的引用，而不是创建新实例。

游戏开始时加载的实例也保存在XML文件中，然后根据元素类型加载到单独的列表中，例如所有ItemEquipmentWeapon实例(继承Item的Inherits ItemEquipment)在一个WeaponItem.aid文件中，该文件是以 XML 格式，并加载到列表中

有什么方法可以通过引用将 Inv 内容保存到播放器保存文件或从播放器保存文件加载，这样我就可以让它们在初始加载期间使用现有实例设置？

编辑:我只是想，了解 Player 类的编码方式可能会对一些人有所帮助，所以这里是:

[Serializable()]
public class Player : Entity
{
    public string Name { get; set; }
    public int MaxHP { get; set; }
    public int Level { get; set; }
    public int XP { get; set; }
    public int Str { get; set; }
    public int End { get; set; }
    public int Dex { get; set; }
    public int Agi { get; set; }
    public int Wis { get; set; }
    public int Int { get; set; }

    public List<Item> Inv { get; set; }

    private ItemEquipmentWeapon lHand;
    private ItemEquipmentWeapon rHand;

    public ItemEquipmentWeapon LHand
    {
        get 
        { return lHand; }
        set
        {
            if (!value.THand)
            {
                lHand = value;
            }
            else lHand = null;
        }
    }
    public ItemEquipmentWeapon RHand
    {
        get 
        { return rHand; }
        set 
        { rHand = value; }
    }

    internal Player() { }
    public Player(string name, int maxhp, int hp, int lvl, int exp, int str, int end, int dex, int agi, int wis, int inte)
        : base(true, hp)
    {
        Name = name;
        MaxHP = maxhp;
        Level = lvl;
        XP = exp;
        Str = str;
        End = end;
        Dex = dex;
        Agi = agi;
        Wis = wis;
        Int = inte;

        Inv = new List<Item>();
    }

    public List<string> GetInv()
    {
        List<string> val = new List<string>();

        foreach (Item item in Inv)
        {
            val.Add(item.Name);
        }

        return val;
    }

    public void AddItem(Item i, int amt)
    {
        for (int j = 0; j < amt; j++)
        {
            Inv.Add(i);
        }
    }
    public void AddItem(Item i){
        AddItem(i, 1); }

    public void RemoveItem(Item i, int amt)
    {
        int count = 0;

        foreach (Item item in Inv)
        {
            if (item == i)
            {
                Inv.Remove(item);
                count++;
            }
            if (count == amt)
            {
                break;
            }
        }
    }
    public void RemoveItem(Item i){
        RemoveItem(i, 1); }

    public bool HasItem(Item i, int amt)
    {
        int count = 0;

        foreach (Item item in Inv)
        {
            if (item == i)
            {
                count++;
            }
        }

        return count >= amt;
    }
    public bool HasItem(Item i){
        return HasItem(i, 1); }
}

显然，在游戏加载时从 XML 加载项目实例的代码也非常有用，但我还没有编写代码，我不是 100% 确定我将如何去做。不过到目前为止，我有这个:

public static class InitLoad
{
    static List<ItemEquipmentWeapon> weapons;

    public static void PreLoading()
    {
        string path, filePath, 
            weaponFile = @"\WeaponsItem.aid";
        XmlSerializer SerializerObj;
        FileStream ReadFileStream;

        path = string.Format(@"{0}\AwesomeRPG\Data\Items",
            Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData));

        filePath = string.Format(@"{0}\{1}", path, weaponFile);
        SerializerObj = new XmlSerializer(typeof(ItemEquipmentWeapon));
        ReadFileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
        weapons = (List<ItemEquipmentWeapon>)SerializerObj.Deserialize(ReadFileStream);
    }
}

在此先感谢您的帮助!

Answer 1

Is there any way I can save and load the Inv contents to and from the player save file by reference so I can have them use the existing instances setup during initial loading?

这是解决这个问题的一种方法:
1. 添加到您的Item类 int领域 Id或类似的东西，并为每个唯一项目分配适当的唯一值。
2. 在初始加载期间，为游戏中的所有独特项目创建一个全局缓存。对于这个问题，我建议使用 Dictionary<int, Item>关键是Id项目和值(value)将是项目本身。
3. 在你的Player你应该只存储类 Id的项目，因此在加载期间您可以获得 Item 的实例来自前面提到的全局缓存。

此外，您可能想阅读有关 flyweight 的内容模式，这几乎与共享实例有关。