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/53768041/custom-serializer-for-just-one-property-in-json-net-without-changing-the-model

    public class ConfigurableContractResolver : DefaultContractResolver

    {

        // This contract resolver taken from the answer to

        // https://stackoverflow.com/questions/46047308/how-to-add-metadata-to-describe-which-properties-are-dates-in-json-net

        // https://stackoverflow.com/a/46083201/3744182

​

        readonly object contractCreatedPadlock = new object();

        event EventHandler<ContractCreatedEventArgs> contractCreated;

        int contractCount = 0;

​

        void OnContractCreated(JsonContract contract, Type objectType)

        {

            EventHandler<ContractCreatedEventArgs> created;

            lock (contractCreatedPadlock)

            {

                contractCount++;

                created = contractCreated;

            }

            if (created != null)

            {

                created(this, new ContractCreatedEventArgs(contract, objectType));

            }

        }

​

        public event EventHandler<ContractCreatedEventArgs> ContractCreated

        {

            add

            {

                lock (contractCreatedPadlock)

                {

                    if (contractCount > 0)

                    {

                        throw new InvalidOperationException("ContractCreated events cannot be added after the first contract is generated.");

                    }

                    contractCreated += value;

                }

            }

            remove

            {

                lock (contractCreatedPadlock)

                {

                    if (contractCount > 0)

                    {

                        throw new InvalidOperationException("ContractCreated events cannot be removed after the first contract is generated.");

                    }

                    contractCreated -= value;

                }

            }

        }

​

        protected override JsonContract CreateContract(Type objectType)

        {

            var contract = base.CreateContract(objectType);

            OnContractCreated(contract, objectType);

            return contract;

        }

    }

​

    public class ContractCreatedEventArgs : EventArgs

    {

        public JsonContract Contract { get; private set; }

        public Type ObjectType { get; private set; }

​

        public ContractCreatedEventArgs(JsonContract contract, Type objectType)

        {

            this.Contract = contract;

            this.ObjectType = objectType;

        }

    }

​

    public static class ConfigurableContractResolverExtensions

    {

        public static ConfigurableContractResolver Configure(this ConfigurableContractResolver resolver, EventHandler<ContractCreatedEventArgs> handler)

        {

            if (resolver == null || handler == null)

                throw new ArgumentNullException();

            resolver.ContractCreated += handler;

            return resolver;

        }

    }

​

    public class Person

    {

        public string FirstName { get; set; }

​

        //[JsonConverter(typeof(AllCapsConverter))]

        public string LastName { get; set; }

        // more properties here in the real example, some of which nest to properties that use their own JsonConverters.

    }

​

    public class AllCapsConverter : JsonConverter

    {

        public override bool CanConvert(Type objectType) { return objectType == typeof(string); }

​

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

​

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

        {

            throw new NotSupportedException();

        }

​

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

        {

            var str = value as string;

            var upper = str.ToUpperInvariant();

            writer.WriteValue(upper);

        }

    }

​

    public static class JsonContractExtensions

    {

        public static void ConfigurePerson(this JsonContract contract)

        {

            if (!typeof(Person).IsAssignableFrom(contract.UnderlyingType))

                return;

            var objectContract = contract as JsonObjectContract;

            if (objectContract == null)

                return;

            // Use nameof in in .Net 4.5 or later

            //var property = objectContract.Properties.Where(p => p.UnderlyingName == nameof(Person.LastName)).Single();

            var property = objectContract.Properties.Where(p => p.UnderlyingName == "LastName").Single();

            property.Converter = new AllCapsConverter();

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            // Cache the contract resolver statically for best performance.

            var resolver = new ConfigurableContractResolver()

                .Configure((s, e) => { e.Contract.ConfigurePerson(); });

​

            var settigs = new JsonSerializerSettings

            {

                ContractResolver = resolver,

            };

​

            var person = new Person

            {

                FirstName = "George",

                LastName = "Washington"

            };

            var serialized = JsonConvert.SerializeObject(person, settigs);

            var expected = @"{""FirstName"":""George"",""LastName"":""WASHINGTON""}";

            Assert.AreEqual(expected, serialized);

​

            Console.WriteLine(serialized);

        }           

    }

​

    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;

            }

        }

    }

​