using System;

using System.Drawing;

using System.Text.Json;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        var rectangle = new Rectangle(1, 2, 3, 4);

        var newtonSoftjsonSerialized = JsonConvert.SerializeObject(rectangle);

        Console.WriteLine(newtonSoftjsonSerialized);

        var jsonOptions = new JsonSerializerOptions

        {

            WriteIndented = true,

            Converters =

            {

                new RectangleJsonConverter()

            }

        };

        var jsonSerialized = System.Text.Json.JsonSerializer.Serialize(rectangle, jsonOptions);

​

        Console.WriteLine(jsonSerialized);

        var fromNewtonsoftSerializedToObjectUsingJson = System.Text.Json.JsonSerializer.Deserialize<Rectangle>(newtonSoftjsonSerialized, jsonOptions);

        Console.WriteLine(fromNewtonsoftSerializedToObjectUsingJson.X);     

        Console.WriteLine(fromNewtonsoftSerializedToObjectUsingJson.Y);     

        Console.WriteLine(fromNewtonsoftSerializedToObjectUsingJson.Width);     

        Console.WriteLine(fromNewtonsoftSerializedToObjectUsingJson.Height);

    }

}

​

    public class RectangleJsonConverter : System.Text.Json.Serialization.JsonConverter<Rectangle>

    {

        public override Rectangle Read(

            ref Utf8JsonReader reader,

            Type typeToConvert,

            JsonSerializerOptions options) {

                var parts = reader.GetString().Split(new string[] { ", " }, StringSplitOptions.None);               

                return new Rectangle(int.Parse(parts[0]), int.Parse(parts[1]), int.Parse(parts[2]), int.Parse(parts[3]));

            }

​

        public override void Write(

            Utf8JsonWriter writer,

            Rectangle rectangle,

            JsonSerializerOptions options) {

                writer.WriteStringValue(rectangle.X + ", " + rectangle.Y + ", " + rectangle.Width + ", " + rectangle.Height);

            }

    }