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 System.Text.Json.Serialization.Metadata;

using System.Text.Json.Nodes;

​

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

​

#nullable enable

​

//https://stackoverflow.com/questions/76263968/c-sharp-parse-byte-to-json-without-converting-to-base64-string

​

    public class ByteArrayConverter : JsonConverter<byte []>

    {

        public override void Write(Utf8JsonWriter writer, byte [] value, JsonSerializerOptions options) =>

            JsonSerializer.Serialize(writer, value.AsEnumerable());

        public override byte []? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) =>

            reader.TokenType switch

            {

                JsonTokenType.String => reader.GetBytesFromBase64(),

                JsonTokenType.StartArray => JsonSerializer.Deserialize<List<byte>>(ref reader)!.ToArray(),

                JsonTokenType.Null => null,

                _ => throw new JsonException(),

            };

    }

​

    public class MyModel

    {

        public int Id { get; set; }

        public byte [] Data { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            MyModel myObject = new MyModel

            {

                Id = 1,                

                Data = new byte[] { 0x01, 0x02, 0x03 }

            };

            var options = new JsonSerializerOptions { Converters = { new ByteArrayConverter() } };

            string json = JsonSerializer.Serialize(myObject, options);

            Console.WriteLine(json);

            var model2 = JsonSerializer.Deserialize<MyModel>(json, options);

            Assert.That(myObject.Data.SequenceEqual(model2!.Data));

            var base64json = JsonSerializer.Serialize(myObject);

            Console.Write("\nTesting deserialization of {0} also... ", base64json);

            var model3 = JsonSerializer.Deserialize<MyModel>(base64json, options);

            Assert.That(myObject.Data.SequenceEqual(model3!.Data));

            Console.WriteLine(" passed.");

        }   

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1}), {2}", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , Environment.Version, Environment.OSVersion);

            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;

            }

        }

    }

​