无法为Microsoft.FSharp.Core.Unit生成自动编码器。请传递额外的编码器

open Newtonsoft.Json
open Newtonsoft.Json.Linq
open Microsoft.FSharp.Core

type UnitConverter() =
    inherit JsonConverter()

    override this.CanConvert(ty : System.Type) =
        ty = typeof<Unit>

    override this.WriteJson(writer : JsonWriter, value : obj, serializer : JsonSerializer) =
        writer.WriteNull()

    override this.ReadJson(reader : JsonReader, ty : System.Type, existingValue : obj, serializer : JsonSerializer) =
        unit

// 使用示例
let settings = JsonSerializerSettings()
settings.Converters.Add(UnitConverter())

let serialized = JsonConvert.SerializeObject(unit, settings)
let deserialized : unit = JsonConvert.DeserializeObject(serialized, typeof<unit>) :?> unit