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 System.Runtime.Serialization;

​

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/59803559/how-to-get-json-property-name-using-reflection-in-c-sharp

​

    public class Employee {

​

        [JsonProperty("emp_id")]

        public int Id {get; set;}

​

        [JsonProperty("emp_fname")]

        public string Name {get;set;}

​

        [JsonProperty("emp_lname")]

        public string LastName {get;set;} 

        public string SomePropertyWithoutJsonPropertyAdded { get; set; }

    }

​

    [JsonObject(NamingStrategyType = typeof(SnakeCaseNamingStrategy))]

    public class SnakeCase {

​

        public int Id {get; set;}

​

        public string Name {get;set;}

​

        public string LastName {get;set;} 

        [JsonProperty(NamingStrategyType = typeof(CamelCaseNamingStrategy))]

        public string SomePropertyWithoutJsonPropertyAdded { get; set; }

    }

​

    [DataContract]

    public class DataContractType {

​

        [DataMember(Name = "emp_id")]

        public int Id {get; set;}

​

        [DataMember(Name = "emp_fname")]

        public string Name {get;set;}

​

        [DataMember(Name = "emp_lname")]

        public string LastName {get;set;} 

        public string SomePropertyWithoutJsonPropertyAdded { get; set; }

    }

​

    public static partial class JsonExtensions

    {

        static readonly IContractResolver defaultResolver = JsonSerializer.CreateDefault().ContractResolver;

        public static object GetJsonProperty<T>(T obj, string jsonName, bool exact = false, IContractResolver resolver = null)

        {

            if (obj == null)

                throw new ArgumentNullException(nameof(obj));

            resolver = resolver ?? defaultResolver;

            var contract = resolver.ResolveContract(obj.GetType()) as JsonObjectContract;

            if (contract == null)

                throw new ArgumentException(string.Format("{0} is not serialized as a JSON object", obj));

            var property = contract.Properties.GetProperty(jsonName, exact ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase);

            if (property == null)

                throw new ArgumentException(string.Format("Property {0} was not found.", jsonName));

            return property.ValueProvider.GetValue(obj); // Maybe check JsonProperty.Readable first, and throw an exception if not?

        }

    }

​

    public static partial class JsonExtensions

    {

        public static string [] PropertyNames(Type type)

        {

            return PropertyNames(defaultResolver, type);

        }

        //Taken from this answer https://stackoverflow.com/a/45829514/3744182

        //To https://stackoverflow.com/questions/33616005/get-a-list-of-json-property-names-from-a-class-to-use-in-a-query-string

        public static string [] PropertyNames(this IContractResolver resolver, Type type)

        {

            if (resolver == null || type == null)

                throw new ArgumentNullException();

            var contract = resolver.ResolveContract(type) as JsonObjectContract;

            if (contract == null)

                return new string[0];

            return contract.Properties.Where(p => !p.Ignored).Select(p => p.PropertyName).ToArray();

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var employee = new Employee

            {

                Id = 101,

                Name = "my name",

                LastName = "last name",

                SomePropertyWithoutJsonPropertyAdded = "Some Property Without JsonProperty Added",

            };

            Console.WriteLine("Value of {0} is {1}.", "emp_lname", 

                              JsonExtensions.GetJsonProperty(employee, "emp_lname")); // Prints Value of emp_lname is last name.

​

            Console.WriteLine("Value of {0} is {1}.", "emp_lname", 

                              JsonExtensions.GetJsonProperty(employee, "emp_lname", resolver : new CamelCasePropertyNamesContractResolver())); 

​

            Test(employee);

            Test(new SnakeCase { Id = 101, Name = "snake case name", LastName = "snake case last name" });

            Test(new DataContractType { Id = 101, Name = "data member name", LastName = "data member last name", SomePropertyWithoutJsonPropertyAdded = "foo" });

        }   

        static void Test<T>(T obj)

        {

            Console.WriteLine("\nTesting all properties of {0}:", obj);

            foreach(var name in JsonExtensions.PropertyNames(obj.GetType()))

            {

                var value = JsonExtensions.GetJsonProperty(obj, name);

                Console.WriteLine("Value of {0} is {1}", name, value);

                Assert.IsTrue(new JTokenEqualityComparer().Equals(JObject.FromObject(obj)[name], value == null ? JValue.CreateNull() : JToken.FromObject(value)));

            }

        }

    }

​

    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;

        }

    }

​