using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using NUnit.Framework;

​

//https://stackoverflow.com/questions/52663623/create-jobject-with-propertyname-subname

​

    class TestClass

    {

        public static void Test()

        {

            var jsonObject = new JObject();

            var userDetails = new JObject();

            jsonObject["UserDetails"] = userDetails;

            userDetails["UserID"] = "123456789";

            userDetails["FirstName"] = "Test1";

            userDetails["Surname"] = "Test2";           

            userDetails["Children1.Active1"] = false;

            userDetails["Children1.Active2"] = false;

            Console.WriteLine(jsonObject);

            Assert.IsTrue(JToken.DeepEquals(jsonObject, JToken.Parse(GetRequiredJSON())));

            Console.WriteLine("Generated and required JSON are identical.");

        }

        static string GetRequiredJSON()

        {

            var json = @"{ ""UserDetails"": {

          ""FirstName"": ""Test1"",

          ""Surname"": ""Test2"",

          ""UserID"": ""123456789"",

          ""Children1.Active1"": false,

          ""Children1.Active2"": false

    }

}";

            return json;

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: " + Environment.Version);

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​