open System

open Newtonsoft.Json

​

type r =

    {

        TransferIn:          int64 option

        TransferOut:         int64 option

    }

let a =

    "{

    \"transferIn\": 1000000,

}"

​

let item : r = { TransferIn = Some 1000000L; TransferOut = None}

let json = JsonConvert.SerializeObject(item,Formatting.Indented)

printfn "%s" json

​

printfn "%s" a

JsonConvert.DeserializeObject<r> a

​

​

​