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/58895039/find-invalid-values-from-jsonreaderexception-in-json-net

​

    public class ErrorAndValueEventArgs : Newtonsoft.Json.Serialization.ErrorEventArgs 

    {

        public object ReaderValue { get; } = null;

        public ErrorAndValueEventArgs(object readerValue, object currentObject, ErrorContext errorContext) : base(currentObject, errorContext)

        {

            this.ReaderValue = readerValue;

        }

    }

    public static partial class JsonExtensions

    {

        public static TRootObject Deserialize<TRootObject>(string json, EventHandler<ErrorAndValueEventArgs> error, JsonSerializerSettings settings = null)

        {

            using (var sr = new StringReader(json))

            using (var jsonReader = new JsonTextReader(sr))

            {

                var serializer = JsonSerializer.CreateDefault(settings);

                serializer.Error += (o, e) => error(o, new ErrorAndValueEventArgs(jsonReader.Value, e.CurrentObject, e.ErrorContext));

                return serializer.Deserialize<TRootObject>(jsonReader);

            }

        }

    }

​

    public class Account

    {

        public string Email { get; set; }

        public bool Active { get; set; }

        public DateTime CreatedDate { get; set; }

        public List<string> Roles { get; set; }

    }

​

    class TestClass

    {

        public static void Test()

        {

            string json = @"{

              'Email': 'james@example.com',

              'Active': 'aaa',

              'CreatedDate': '2013-01-20T00:00:00Z',

              'Roles': [

                'User',

                'Admin'

              ]

            }";         

            Console.WriteLine("Input JSON: ");

            Console.WriteLine(JToken.Parse(json));

            object errorValue = null;

            try

            {

                Account account = JsonExtensions.Deserialize<Account>(json, (o, e) => errorValue = e.ReaderValue);

                Console.WriteLine(account.Email);

            }

            catch (JsonException exc)

            {

                // Do Something

                Console.WriteLine("Value at time of {0} = {1}, Data.Count = {2}.", exc.GetType().Name, errorValue, exc.Data.Count);

                // Prints Value at time of JsonReaderException = aaa, Data.Count = 0.

            }

        }

    }

​

    public class Program

    {

        public static void Main()

        {

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

            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 static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.CodeBase.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​