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 Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;        

// https://stackoverflow.com/questions/45096112/parsing-a-dynamically-changing-json-file-in-c-sharp

​

    public class TestClass

    {

        static IEnumerable<string> GetJson()

        {

            var json = new []

            {

                @"{

  ""parent"": 

    {

      ""child"": {

        ""key1"": ""value1 value"",

        ""key2"": ""value2""

      }

    }  

}",

​

                @"{

  ""parent"": [

    {

      ""child"": {

        ""key1"": ""value1 value"",

        ""key2"": ""value2""

      }

    },

    {

​

      ""child"": {

        ""key1"": ""value1"",

        ""key2"": ""value2""

      }

    }

  ]

}",             

            };

​

            return json;    

        }

        public static void Test()

        {

            foreach (var json in GetJson())

            {

                Console.WriteLine("Testing: ");

                Console.WriteLine(json);

                TestExtensionMethod(json);

                TestSelectTokens(json);

                Console.WriteLine();

            }

        }

        public static void TestExtensionMethod(string json)

        {

            var jsonfile = JToken.Parse(json);

​

            var child = jsonfile["parent"].SingleOrArrayItems().FirstOrDefault();

            var value1 = child == null ? null : child.SelectToken("child.key1");

​

            Console.WriteLine("Result of extension method:");

            Console.WriteLine(value1);

        }

        public static void TestSelectTokens(string json)

        {

            var jsonfile = JToken.Parse(json);

            var value1 = jsonfile.SelectTokens("parent..child.key1").FirstOrDefault();

​

            Console.WriteLine("Result of SelectTokens:");           

            Console.WriteLine(value1);

        }

    }

​

​

        public static class JsonExtensions

        {

            public static IEnumerable<JToken> SingleOrArrayItems(this JToken source)

            {

                if (source == null || source.Type == JTokenType.Null)

                    return Enumerable.Empty<JToken>();

                IEnumerable<JToken> arr = source as JArray;

                return arr ?? new[] { source };

            }

        }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: " + Environment.Version);

            Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            TestClass.Test();

        }

    }

​

​