using System;

using MessagePack;

​

[MessagePackObject]

public class UserV1

{

    [Key(0)]

    public long Id { get; set; }

​

    [Key(1)]

    public long AccountId { get; set; }

​

    [Key(2)]

    public bool UseSuperSafeConversationMode { get; set; }

​

    public override string ToString()

    {

        return $"{nameof(Id)}: {Id}, {nameof(AccountId)}: {AccountId}, {nameof(UseSuperSafeConversationMode)}: {UseSuperSafeConversationMode}";

    }

}

​

[MessagePackObject]

public class UserV2

{

    [Key(0)]

    public long Id { get; set; }

​

    [Key(1)]

    public long AccountId { get; set; }

​

    // [Key(2)]

    // public bool UseSuperSafeConversationMode { get; set; }

    [Key(3)]

    public string Name { get; set; }

​

    public override string ToString()

    {

        return $"{nameof(Id)}: {Id}, {nameof(AccountId)}: {AccountId}, {nameof(Name)}: {Name}";

    }

}

​

public class Program

{

    public static void Main()

    {

        {

            Console.WriteLine("V1 -> V2");

            var user = new UserV1

            {

                Id = 123,

                AccountId = 234,

                UseSuperSafeConversationMode = false

            };

            var bytes = MessagePackSerializer.Serialize(user);

            var userV1 = MessagePackSerializer.Deserialize<UserV1>(bytes);

            var userV2 = MessagePackSerializer.Deserialize<UserV2>(bytes);

            var json = MessagePackSerializer.ConvertToJson(bytes);

            Console.WriteLine(json);

            Console.WriteLine(userV1.ToString());

            Console.WriteLine(userV2.ToString());

        }

​

        {

            Console.WriteLine("V2 -> V1");

            var user = new UserV2

            {

                Id = 123,

                AccountId = 234,

                Name = "Username"

            };

            var bytes = MessagePackSerializer.Serialize(user);

            var userV1 = MessagePackSerializer.Deserialize<UserV1>(bytes);

            var userV2 = MessagePackSerializer.Deserialize<UserV2>(bytes);

            var json = MessagePackSerializer.ConvertToJson(bytes);

            Console.WriteLine(json);

            Console.WriteLine(userV1.ToString());

            Console.WriteLine(userV2.ToString());

        }

    }

}