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; // Throws NUnit.Framework.AssertionException

​

    //https://stackoverflow.com/questions/54205858/json-skip-deserializing-string-into-listobject-if-member-is-missing

​

    public interface IMachineInfo

    {

    }

​

    public class Machine1 : IMachineInfo

    {

        public double powerWatts { get; set; }

        public double radiation { get; set; }

        public double current { get; set; }

    }

​

    public class Machine2 : IMachineInfo

    {

        public double dbm { get; set; }

        public double magneticField { get; set; }

        public double frequency { get; set; }

    }

​

    public abstract class JsonListItemTypeInferringConverterBase<TItem> : JsonConverter

    {

        public override bool CanWrite { get { return false; } }

​

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

        {

            throw new NotImplementedException();

        }

​

        protected abstract bool TryInferItemType(Type objectType, JToken json, out Type type);

​

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

        {

            // Get contract information

            var contract = serializer.ContractResolver.ResolveContract(objectType) as JsonArrayContract;

            if (contract == null || contract.IsMultidimensionalArray || objectType.IsArray)

                throw new JsonSerializationException(string.Format("Invalid array contract for {0}", objectType));

​

            if (reader.MoveToContent().TokenType == JsonToken.Null)

                return null;

​

            if (reader.TokenType != JsonToken.StartArray)

                throw new JsonSerializationException(string.Format("Expected {0}, encountered {1} at path {2}", JsonToken.StartArray, reader.TokenType, reader.Path));

​

            var collection = existingValue as IList<TItem> ?? (IList<TItem>)contract.DefaultCreator();

​

            // Process the collection items

            while (reader.Read())

            {

                switch (reader.TokenType)

                {

                    case JsonToken.EndArray:

                        return collection;

​

                    case JsonToken.Comment:

                        break;

​

                    default:

                        {

                            var token = JToken.Load(reader);

                            Type itemType;

                            if (!TryInferItemType(typeof(TItem), token, out itemType))

                                break;

                            collection.Add((TItem)serializer.Deserialize(token.CreateReader(), itemType));

                        }

                        break;

                }

            }

            // Should not come here.

            throw new JsonSerializationException("Unclosed array at path: " + reader.Path);

        }

​

        public override bool CanConvert(Type objectType)

        {

            return objectType.IsAssignableFrom(typeof(List<TItem>));

        }

    }

​

    public static partial class JsonExtensions

    {

        public static JsonReader MoveToContent(this JsonReader reader)

        {

            while ((reader.TokenType == JsonToken.Comment || reader.TokenType == JsonToken.None) && reader.Read())

                ;

            return reader;

        }

    }

​

    public class Machine1ListConverter<TMachineInfo> : JsonListItemTypeInferringConverterBase<TMachineInfo> where TMachineInfo : IMachineInfo

    {

        protected override bool TryInferItemType(Type objectType, JToken json, out Type type)

        {

            var obj = json as JObject;

            if (obj != null && obj.GetValue("powerWatts", StringComparison.OrdinalIgnoreCase) != null)

            {

                type = typeof(Machine1);

                return true;

            }

            type = null;

            return false;

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            TestInterface();

            TestConcrete();

        }

​

        static void TestInterface()

        {

            var jsonString = GetJson();

​

            var settings = new JsonSerializerSettings

            {

                Converters = { new Machine1ListConverter<IMachineInfo>() },

            };

            var list = JsonConvert.DeserializeObject<List<IMachineInfo>>(jsonString, settings);

​

            Console.WriteLine("De-serialized and reserialized {0}: ", list.GetType().FullName);

            Console.WriteLine(JsonConvert.SerializeObject(list, Formatting.Indented));

​

            Assert.IsTrue(list.Count == JArray.Parse(jsonString).SelectTokens("[*].powerWatts").Count());

        }

​

        static void TestConcrete()

        {

            var jsonString = GetJson();

​

            var settings = new JsonSerializerSettings

            {

                Converters = { new Machine1ListConverter<Machine1>() },

            };

            var list = JsonConvert.DeserializeObject<List<Machine1>>(jsonString, settings);

​

            Console.WriteLine("De-serialized and reserialized {0}: ", list.GetType().FullName);

            Console.WriteLine(JsonConvert.SerializeObject(list, Formatting.Indented));

​

            Assert.IsTrue(list.Count == JArray.Parse(jsonString).SelectTokens("[*].powerWatts").Count());

        }

​

        static string GetJson()

        {

            var json = @"[

  {

    ""windowsTime"": ""2019-01-14T18:47:55.8390256-06:00"",

    ""irigTime"": ""0001-01-01T00:00:00"",

    ""messageTypeFlag"": ""Q"",

    ""sequenceNum"": 0,

  },

  {

    ""dbm"": ""66"",

    ""magneticField "": ""8967"",

    ""frequency"": ""34500"",

    ""windowsTime"": ""2019-01-14T18:47:55.8390256-06:00"",

    ""irigTime"": ""0001-01-01T00:00:00"",

    ""messageTypeFlag"": ""Q"",

    ""sequenceNum"": 0,

  },

  {

    ""powerWatts"": ""4000"",

    ""radiation"": ""67"",

    ""current"": ""2478"",

    ""windowsTime"": ""2019-01-14T18:47:55.8390256-06:00"",

    ""irigTime"": ""0001-01-01T00:00:00"",

    ""messageTypeFlag"": ""Q"",

    ""sequenceNum"": 0,

  },

  {

    ""powerWatts"": ""4000"",

    ""radiation"": ""67"",

    ""current"": ""2478"",

    ""windowsTime"": ""2019-01-14T18:47:55.8390258-06:00"",

    ""irigTime"": ""0001-01-01T00:00:00"",

    ""messageTypeFlag"": ""Q"",

    ""sequenceNum"": 0,

   }

]";

            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;

            }

        }

    }

​