using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

​

using System.Text.Json;

using System.Text.Json.Serialization;

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/66495660/net-5-0-signature-change-of-system-text-json-jsonserializer-deserialize

​

    internal class Student {

        public int Id { get; set; }

        public string Name { get; set; }

        public string ContactPhone { get; set; }

​

        public IEnumerable<MedicalRecord> MedicalRecords { get; set; }

    }

​

    internal class MedicalRecord {

        public int Id { get; set; }

        public string Name { get; set; }

        public DateTime RecordDate { get; set; }

        public IEnumerable<DiseaseLog> DiseaseLogs{ get; set; }

    }

​

    internal class DiseaseLog {

        public int Id { get; set; }

        public string Name { get; set; }

        public DateTime LogDate { get; set; }

    }

​

    public class RootObject

    {

        public object students { get; set; }

​

        [System.Text.Json.Serialization.JsonExtensionDataAttribute]

        public IDictionary<string, object> ExtensionData { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var students = new List<Student> { // Initialize these as required...

                new ()

                {

                    Id = 1,

                    Name = "Wilson",

                    ContactPhone = "123-122-3311",

                    MedicalRecords = new List<MedicalRecord>()

                    {

                        new ()

                        {

                            Id = 101,

                            Name = "Medial record 101011",

                            RecordDate = new DateTime(2021, 12, 31),

                            DiseaseLogs = new List<DiseaseLog>()

                            {

                                new ()

                                {

                                    Id = 18211,

                                    Name = "Patient Log 19292",

                                    LogDate = new DateTime(2020, 1, 31),

                                },

                                new () 

                                {

                                    Id = 18212,

                                    Name = "Patient Log 2911w",

                                    LogDate = new DateTime(2020, 3, 31),

                                }

                            },

                        },

                    },

                }

            };

​

            var dynamicJson = @"{""roomid"":1,""roomcode"":""Code001"",""students"":[1],""contentdata"":""say hello"",""footerdata"":""cookie policy""}";

            var root = JsonSerializer.Deserialize<RootObject>(dynamicJson);

​

            root.students = students;

            var modifyJson = JsonSerializer.Serialize(root, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, WriteIndented = true });

            Console.WriteLine(modifyJson);

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version);

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

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

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

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​