如何使JsonConverter写入键/值而不是键/数组

我有包含标识符的类，如下所示

public class Type1
{
    public int Id { get; set; }
    // other properties
}

public class Type2
{
    public int Id { get; set; }
    // other properties
}

public class ParentType
{
    [JsonConverter(typeof(IdConverter))]
    public Type1 Instance1 { get; set; }

    [JsonConverter(typeof(IdConverter))]
    public Type2 Instance2 { get; set; }
}

class IdConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        PropertyInfo pi = objectType.GetProperty("Id");
        return (pi != null && pi.PropertyType == typeof(int));
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        JToken t = JToken.FromObject(value);

        if (t.Type != JTokenType.Object)
        {
            t.WriteTo(writer);
        }
        else
        {
            int id = (int)value.GetType().GetProperty("Id").GetValue(value);
            JObject o = JObject.FromObject(new { Id = id });
            o.WriteTo(writer);
        }
    }
}

{
  "Instance1": 1,
  "Instance2": 2
}

{
  "Instance1": 1,
  "Instance2": 2
}

我想将

父类型

序列化为Json，但不需要序列化整个类。我只需要Id，因为它唯一标识实例。IdConverter是这样实现的

public class Type1
{
    public int Id { get; set; }
    // other properties
}

public class Type2
{
    public int Id { get; set; }
    // other properties
}

public class ParentType
{
    [JsonConverter(typeof(IdConverter))]
    public Type1 Instance1 { get; set; }

    [JsonConverter(typeof(IdConverter))]
    public Type2 Instance2 { get; set; }
}

class IdConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        PropertyInfo pi = objectType.GetProperty("Id");
        return (pi != null && pi.PropertyType == typeof(int));
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        JToken t = JToken.FromObject(value);

        if (t.Type != JTokenType.Object)
        {
            t.WriteTo(writer);
        }
        else
        {
            int id = (int)value.GetType().GetProperty("Id").GetValue(value);
            JObject o = JObject.FromObject(new { Id = id });
            o.WriteTo(writer);
        }
    }
}

{
  "Instance1": 1,
  "Instance2": 2
}

{
  "Instance1": 1,
  "Instance2": 2
}

这很好，但输出Json的格式并不理想

{
  "Instance1": {
    "Id": 1
  },
  "Instance2": {
    "Id": 2
  }
}

我希望它看起来更像这样

public class Type1
{
    public int Id { get; set; }
    // other properties
}

public class Type2
{
    public int Id { get; set; }
    // other properties
}

public class ParentType
{
    [JsonConverter(typeof(IdConverter))]
    public Type1 Instance1 { get; set; }

    [JsonConverter(typeof(IdConverter))]
    public Type2 Instance2 { get; set; }
}

class IdConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        PropertyInfo pi = objectType.GetProperty("Id");
        return (pi != null && pi.PropertyType == typeof(int));
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        JToken t = JToken.FromObject(value);

        if (t.Type != JTokenType.Object)
        {
            t.WriteTo(writer);
        }
        else
        {
            int id = (int)value.GetType().GetProperty("Id").GetValue(value);
            JObject o = JObject.FromObject(new { Id = id });
            o.WriteTo(writer);
        }
    }
}

{
  "Instance1": 1,
  "Instance2": 2
}

{
  "Instance1": 1,
  "Instance2": 2
}

---

有什么办法可以做到这一点吗？

对不起，我自己解决的

public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
    JToken t = JToken.FromObject(value);

    if (t.Type != JTokenType.Object)
    {
        t.WriteTo(writer);
    }
    else
    {
        int id = (int)value.GetType().GetProperty("Id").GetValue(value);
        writer.WriteValue(id);
    }
}

结果