Unity中Newtonsoft.Json加载自定义GraphNode字典报错求助

我正在开发Unity项目，需要实现键为自定义类型GraphNode、值为同类型List<GraphNode>的字典Dictionary<GraphNode, List<GraphNode>>的保存与加载功能，采用Newtonsoft.Json库进行JSON序列化与反序列化。目前保存操作可正常完成，但执行加载逻辑时触发报错：

Newtonsoft.Json.JsonSerializationException：无法将字符串'GraphNode'转换为字典键类型'GraphNode'。请创建TypeConverter以将字符串转换为键类型对象。路径'allGraphNodes.GraphNode'，第5行，第16位。---> Newtonsoft.Json.JsonSerializationException：将值"GraphNode"转换为类型'GraphNode'时出错。路径'allGraphNodes.GraphNode'，第5行，第16位。---> System.ArgumentException：无法从System.String强制转换或转换为GraphNode。

相关代码 #

GameData脚本 #

using System;
using System.Collections.Generic;

[Serializable]
public class GameData
{
    public Dictionary<GraphNode, List<GraphNode>> allGraphNodes;

    public GameData()
    {
        allGraphNodes = new Dictionary<GraphNode, List<GraphNode>>();
    }
}

GraphNode类 #

public class GraphNode
{
    public enum Type
    {
        entrance = 0,
        enemy = 1,
        hub = 2,
        shop = 3,
        boss = 4
    }

    public Type type;

    public GraphNode(Type type2)
    {
        SetType(type2);
    }

    public void SetType(Type type2)
    {
        type = type2;
    }
}

保存方法 #

public void Save(GameData data)
{
    string text = Path.Combine(dataDirPath, dataFileName);
    try
    {
        Directory.CreateDirectory(Path.GetDirectoryName(text));
        string text3 = JsonConvert.SerializeObject(data, Formatting.Indented, new JsonSerializerSettings
        {
            TypeNameHandling = TypeNameHandling.All,
            TypeNameAssemblyFormatHandling = TypeNameAssemblyFormatHandling.Simple
        });
        if (useEncryption)
        {
            text3 = EncryptDecrypt(text3);
        }
        using FileStream stream = new FileStream(text, FileMode.Create);
        using StreamWriter streamWriter = new StreamWriter(stream);
        streamWriter.Write(text3);
    }
    catch (Exception ex)
    {
        Debug.LogError("Error" + text + "\n" + ex);
    }
}

加载方法 #

public GameData LoadLayout()
{
    string text = Path.Combine(dataDirPath, dataFileName);
    GameData result = null;
    if (File.Exists(text))
    {
        try
        {
            string text2 = "";
            using (FileStream stream = new FileStream(text, FileMode.Open))
            {
                using StreamReader streamReader = new StreamReader(stream);
                text2 = streamReader.ReadToEnd();
                Debug.Log(text2);
            }
            if (useEncryption)
            {
                text2 = EncryptDecrypt(text2);
            }
            result = JsonConvert.DeserializeObject<GameData>(text2, new JsonSerializerSettings //important line
            {
                TypeNameHandling = TypeNameHandling.All,
                TypeNameAssemblyFormatHandling = TypeNameAssemblyFormatHandling.Simple
            });

            return result;
        }
        catch (Exception ex)
        {
            Debug.LogError("Error" + text + "\n" + ex);
            return result;
        }
    }
    return result;
}

保存后的JSON示例 #

{
  "$type": "GameData, Assembly-CSharp",
  "allGraphNodes": {
    "$type": "System.Collections.Generic.Dictionary`2[[GraphNode, Assembly-CSharp],[System.Collections.Generic.List`1[[GraphNode, Assembly-CSharp]], mscorlib]], mscorlib",
    "GraphNode": {
      "$type": "System.Collections.Generic.List`1[[GraphNode, Assembly-CSharp]], mscorlib",
      "$values": [
        {
          "$type": "GraphNode, Assembly-CSharp",
          "type": 1
        }
      ]
    }
  }
}

内容的提问来源于stack exchange，提问作者Benjamin Govedarovic