questions/46293907/create-custom-json-converter-using-newtonsoft-json-library-to-get-additional-dat

CSharp · Console

/Program.cs

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 Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Serialization;	

//     // https://stackoverflow.com/questions/46293907/create-custom-json-converter-using-newtonsoft-json-library-to-get-additional-dat


    class AbcDTO
    {
        public AbcDTO() { this.AdditionalData = new Dictionary<string, object>(); }

        public string Prop1 { get; set; }
        public string Prop2 { get; set; }
        //public List<AdditionalProperty> AdditionalData { get; set; }

        [JsonExtensionData]
        public Dictionary<string, object> AdditionalData { get; private set; }
    }

    class TestClass
    {
        public static void Test()
        {
            var json = GetJson();

            var dto = JsonConvert.DeserializeObject<AbcDTO>(json);

            var json2 = JsonConvert.SerializeObject(dto, Formatting.Indented);

            Console.WriteLine(json2);

            // Assert all the values are primitives.
            Console.WriteLine(string.Format("Dictionary value types: {0}", String.Join(",", dto.AdditionalData.Values.Select(v => v == null ? "null" : v.GetType().ToString()))));
            Assert.IsTrue(!dto.AdditionalData.Values.OfType<JToken>().Any(), "Some values were of type JToken!");
            Console.WriteLine("No dictionary values were of type JToken.");
        }

        static string GetJson()
        {
            var json = @"{
    ""Prop1"": ""Val1"",
    ""Prop2"": ""Val2"",
    ""AdditionalProp3"": ""Val3"",
    ""AdditionalProp4"": ""Val4"",
    ""AdditionalProp5"": 1010101,
    ""AdditionalProp6"": true,
    ""AdditionalProp7"": null,
    ""AdditionalProp8"": ""2012-03-19T07:22Z"",
}
";
            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;
			}
		}
	}

    public class AssertionFailedException : System.Exception
    {
        public AssertionFailedException() : base() { }

        public AssertionFailedException(string s) : base(s) { }
    }

    public static class Assert
    {
        public static void IsTrue(bool value)
        {
            IsTrue(value, "failed");
        }

        public static void IsTrue(bool value, string message)
        {
            if (value == false)
                throw new AssertionFailedException(message ?? "failed");
        }
    }