Csharp JSON串行化程序问题.SQLite中的空值

在DBContext i的OnModelCreating方法中指定了转换选项:

modelBuilder.Entity<Game>()
    .Property(g => g.Players)
    .HasColumnName("Players")
    .HasColumnType("BLOB")
    .HasConversion(
        v => JsonSerializer.Serialize(v, options),
        s => JsonSerializer.Deserialize<Dictionary<string, Player>>(s, options)!,
        ValueComparer.CreateDefault(typeof(Dictionary<string, Player>), true));

Player class个

public class Player {
    public string UserID;
    public string UserName;
    public string UserToken;
    public byte InGameOrder;
    public string Team;
    public List<Cards> Hand;
    public Player(string id, string name, string token, int inGameOrder) {
        UserID = id;
        UserName = name;
        UserToken = token;
        InGameOrder = (byte)inGameOrder;
        Team = new string[] { "red", "black" }[inGameOrder % 2];
        Hand = new(8);
    }
    public Player()
    {
        
    }
}

How I add players:个

var gameFound = await db.Games.FindAsync(sessionName);

if (gameFound.Players.Count() == 0)
{
    gameFound.Players.Add(userToken, new Player(userID, userName, userToken, 1));
}
else
{
    var prevPlayerInGameOrder = gameFound.Players.Values.Select(p => p.InGameOrder).Max();
    gameFound.Players.Add(userToken, new Player(userID, userToken, userName, prevPlayerInGameOrder + 1));
}

db.Games.Update(gameFound);
int affected = await db.SaveChangesAsync();

但数据库中我的球员字典的值是空的:

{"667440114":{},"181308099":{},"1326342467":{}}

我已经有了"类型的反序列化构造函数中的每个参数必须在反序列化时绑定到对象属性或字段"，所以我在Player个类中添加了一个无参数的ctor

我想，我需要在序列化参数中指定ctor为Player