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 System.Collections.ObjectModel;

​

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/67608176/deserializing-large-json-from-webservice-using-json-net

​

    public interface IJsonReaderFilter

    {

        public bool ShouldDeserializeToken(JsonReader reader);

    }

​

    public static class JsonExtensions

    {

        public static IEnumerable<T> DeserializeSelectedTokens<T>(Stream stream, IJsonReaderFilter filter, JsonSerializerSettings settings = null, bool leaveOpen = false)

        {

            using (var sr = new StreamReader(stream, leaveOpen : leaveOpen))

            using (var reader = new JsonTextReader(sr))

                foreach (var item in DeserializeSelectedTokens<T>(reader, filter, settings))

                    yield return item;

        }

​

        public static IEnumerable<T> DeserializeSelectedTokens<T>(JsonReader reader, IJsonReaderFilter filter, JsonSerializerSettings settings = null)

        {

            var serializer = JsonSerializer.CreateDefault(settings);

            while (reader.Read())

                if (filter.ShouldDeserializeToken(reader))

                    yield return serializer.Deserialize<T>(reader);

        }

    }

​

    class ResultsFilter : IJsonReaderFilter

    {

        const string path = "d.results";

        const int pathDepth = 2;

        bool inArray = false;

​

        public bool ShouldDeserializeToken(JsonReader reader)

        {

            if (!inArray && reader.Depth == pathDepth && reader.TokenType == JsonToken.StartArray && string.Equals(reader.Path, "d.results", StringComparison.OrdinalIgnoreCase))

            {

                inArray = true;

                return false;

            }

            else if (inArray && reader.Depth == pathDepth + 1 && reader.TokenType == JsonToken.StartObject)

                return true;

            else if (inArray && reader.Depth == pathDepth && reader.TokenType == JsonToken.EndArray)

            {

                inArray = false;

                return false;

            }

            else

            {

                return false;

            }

        }

    }

​

    public class Metadata

    {

        public string id { get; set; }

        public string uri { get; set; }

        public string type { get; set; }

    }

​

    public class Result

    {

        public Metadata metadata { get; set; }

        public string ID { get; set; }

        public string Value1 { get; set; }

        public string Value2 { get; set; }

        public string Value3 { get; set; }

    }

​

​

    class TestClass

    {

        public static void Test()

        {

            Stream dataStream = new MemoryStream(Encoding.UTF8.GetBytes(GetJson()));

​

            foreach (var result in JsonExtensions.DeserializeSelectedTokens<Result>(dataStream, new ResultsFilter()))

            {

                // Process each result in some manner.

                result.Dump();

            }

        }   

        static string GetJson()

        {

            return @"{

    ""d"": {

        ""results"": [

            {

                ""metadata"": {

                    ""id"": ""1"",

                    ""uri"": """",

                    ""type"": """"

                },

                ""ID"": ""11"",

                ""Value1"": """",

                ""Value2"": """",

                ""Value3"": """"

            },

            {

                ""metadata"": {

                    ""id"": ""2"",

                    ""uri"": """",

                    ""type"": """"

                },

                ""ID"": ""22"",

                ""Value1"": """",

                ""Value2"": """",

                ""Value3"": """"

            },

        ]

    }

}

";

        }

    }

​

    public class Program

    {

        public static void Main()

        {

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

            Console.WriteLine("{0} version: {1}", typeof(JsonSerializer).Assembly.GetName().Name,  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.Location.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;

        }

    }

​