Json.NETでプロパティ名を変更してシリアライズ・デシリアライズ（JsonPropertyAttribute）

gistfile1.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using Newtonsoft.Json;

namespace ConsoleApp {
	class User {
		[JsonProperty("first_name")]
		public string FirstName { get; set; }

		[JsonProperty("last_name")]
		public string LastName { get; set; }

		public override string ToString() {
			return string.Format(@"{{
  FirstName = ""{0}"",
  LastName = ""{1}""
}}", FirstName, LastName);
		}
	}

	class Program {
		static void Main(string[] args) {
			var user = new User {
				FirstName = "悟空",
				LastName = "孫"
			};

			// シリアライズ
			var settings = new JsonSerializerSettings {
				Formatting = Formatting.Indented
			};
			var json = JsonConvert.SerializeObject(user, settings);
			Console.WriteLine(json);
			// {
			//   "first_name": "悟空",
			//   "last_name": "孫"
			// }

			// デシリアライズ
			Console.WriteLine(JsonConvert.DeserializeObject<User>(json));
			// {
			//   FirstName = "悟空",
			//   LastName = "孫"
			// }
		}
	}
}