Protobuf-net v3 DateTimeOffset Surrogate - .net-core

Question

I've seen some other SO's where people are using DateTimeOffset surrogates to handle deserializing those properties, however when I try to copy those, I continue to get a System.InvalidOperationException: No serializer defined for type: System.DateTimeOffset error.
[ProtoContract]
public TestClass
{
[ProtoMember(1)]
public DateTimeOffset Time { get; set; }
}
Surrogate class
[ProtoContract]
public class DateTimeOffsetSurrogate
{
[ProtoMember(1)]
public long DateTimeTicks { get; set; }
[ProtoMember(2)]
public short OffsetMinutes { get; set; }
public static implicit operator DateTimeOffsetSurrogate(DateTimeOffset value)
{
return new DateTimeOffsetSurrogate
{
DateTimeTicks = value.Ticks,
OffsetMinutes = (short)value.Offset.TotalMinutes
};
}
public static implicit operator DateTimeOffset(DateTimeOffsetSurrogate value)
{
return new DateTimeOffset(value.DateTimeTicks, TimeSpan.FromMinutes(value.OffsetMinutes));
}
}
Then I'm registering it right before the http call. I've tried moving this registration into a few different places but it doesn't seem to make a difference. Did this change in v3 or something or am I doing something wrong? Sorry - new to protobuf-net :)
public async Task<Response<IEnumerable<TestClass>>> GetData()
{
RuntimeTypeModel.Default.Add(typeof(DateTimeOffset), false).SetSurrogate(typeof(DateTimeOffsetSurrogate));
var request = new HttpRequestMessage(HttpMethod.Get, "my-url");
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/x-protobuf"));
var result = await _httpClient.SendAsync(request);
var items= ProtoBuf.Serializer.Deserialize<Response<IEnumerable<TestClass>>>(await result.Content.ReadAsStreamAsync());
return items;
}

Answer 1

I am using version 3.1.22 (Currently the latest) of protobuf-net right now with the following setup.
// Needs to be only called at application startup, e.g. in the Startup.cs calls of your web API.
RuntimeTypeModel.Default.Add(typeof(DateTimeOffset), false).SetSurrogate(typeof(DateTimeOffsetSurrogate));
RuntimeTypeModel.Default.Add(typeof(DateTimeOffset?), false).SetSurrogate(typeof(DateTimeOffsetSurrogate));
The surrogate handler I use successfully, can be found below. No black magic happening here, just serializing / deserializing the unix timestamp to long and vice versa:
namespace Something
{
using System;
using ProtoBuf;
/// <summary>
/// A surrogate handler for the <see cref="DateTimeOffset"/> class.
/// </summary>
[ProtoContract(Name = nameof(DateTimeOffset))]
public class DateTimeOffsetSurrogate
{
/// <summary>
/// Gets or sets the value.
/// </summary>
[ProtoMember(1)]
public long? Value { get; set; }
/// <summary>
/// Converts the <see cref="DateTimeOffsetSurrogate"/> to a <see cref="DateTimeOffset"/>.
/// </summary>
/// <param name="surrogate">The surrogate handler.</param>
public static implicit operator DateTimeOffset(DateTimeOffsetSurrogate surrogate)
{
if (surrogate?.Value is null)
{
throw new ArgumentNullException(nameof(surrogate));
}
var dt = DateTimeOffset.FromUnixTimeMilliseconds(surrogate.Value.Value);
dt = dt.ToLocalTime();
return dt;
}
/// <summary>
/// Converts the <see cref="DateTimeOffsetSurrogate"/> to a <see cref="DateTimeOffset"/>.
/// </summary>
/// <param name="surrogate">The surrogate handler.</param>
public static implicit operator DateTimeOffset?(DateTimeOffsetSurrogate? surrogate)
{
if (surrogate?.Value is null)
{
return null;
}
var dt = DateTimeOffset.FromUnixTimeMilliseconds(surrogate.Value.Value);
dt = dt.ToLocalTime();
return dt;
}
/// <summary>
/// Converts the <see cref="DateTimeOffset"/> to a <see cref="DateTimeOffsetSurrogate"/>.
/// </summary>
/// <param name="source">The source.</param>
public static implicit operator DateTimeOffsetSurrogate(DateTimeOffset source)
{
return new DateTimeOffsetSurrogate
{
Value = source.ToUnixTimeMilliseconds()
};
}
/// <summary>
/// Converts the <see cref="DateTimeOffset"/> to a <see cref="DateTimeOffsetSurrogate"/>.
/// </summary>
/// <param name="source">The source.</param>
public static implicit operator DateTimeOffsetSurrogate(DateTimeOffset? source)
{
return new DateTimeOffsetSurrogate
{
Value = source?.ToUnixTimeMilliseconds()
};
}
}
}
Maybe, you want to give it a try. Maybe [ProtoContract(Name = nameof(DateTimeOffset))] is what you're missing, but I'm not sure.