NServicebus not unable to resolve service for interface in handler - .net-core

Question

I'm trying to build my first NserviceBus application, but I cannot get it to work. The message arrives on the "backend" but the handler uses DI and NServicebus claims it cannot find the service for the interface. But the code was lifted directly from the examples. I'm missing something and I cannot figure it out.
The Error:
dbug: NServiceBus.LoadHandlersConnector[0]
Processing message type: Messages.JobStartCommand
Message headers:
NServiceBus.MessageId : 0044f261-e3b3-4287-b6f0-ad7400ef43cb
NServiceBus.MessageIntent : Send
NServiceBus.ConversationId : bb4f276f-63fe-450b-b234-ad7400ef43cd
NServiceBus.CorrelationId : 0044f261-e3b3-4287-b6f0-ad7400ef43cb
NServiceBus.ReplyToAddress : ClientUI
NServiceBus.OriginatingMachine : L19002992
NServiceBus.OriginatingEndpoint : ClientUI
$.diagnostics.originating.hostid : e1fecb2b72b8185e47341bb4dfb37dd7
NServiceBus.ContentType : text/xml
NServiceBus.EnclosedMessageTypes : Messages.JobStartCommand, Messages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
NServiceBus.Version : 7.5.0
NServiceBus.TimeSent : 2021-07-29 14:31:08:228497 Z
NServiceBus.Retries : 3
NServiceBus.Retries.Timestamp : 2021-07-29 14:31:40:397277 Z
Handlers to invoke:
Extractor.JobStartHandler
Extractor.JobStartHandler
info: NServiceBus.RecoverabilityExecutor[0]
Immediate Retry is going to retry message '0044f261-e3b3-4287-b6f0-ad7400ef43cb' because of an exception:
System.InvalidOperationException: Unable to resolve service for type 'IExtract' while attempting to activate 'Extractor.JobStartHandler'.
at Microsoft.Extensi
My backend program.cs
using Microsoft.Extensions.Hosting;
using System;
using System.Diagnostics;
using System.Linq;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using NServiceBus;
using System.Threading.Tasks;
using Messages;
using Extractor;
namespace ExtractorOsiris
{
class Program
{
static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args)
{
var builder = Host.CreateDefaultBuilder(args);
builder.UseWindowsService();
//builder.UseMicrosoftLogFactoryLogging();
builder.ConfigureLogging((ctx, logging) =>
{
logging.AddConfiguration(ctx.Configuration.GetSection("Logging"));
//logging.AddEventLog();
logging.AddConsole();
logging.SetMinimumLevel(LogLevel.Debug);
});
#region back-end-use-nservicebus
builder.UseNServiceBus(ctx =>
{
var endpointConfiguration = new EndpointConfiguration("Sample.Extractor");
endpointConfiguration.UseTransport<LearningTransport>();
var transport = endpointConfiguration.UseTransport<LearningTransport>();
transport.Routing().RouteToEndpoint(typeof(ProcessObjectCommand), "Sample.Processor");
endpointConfiguration.DefineCriticalErrorAction(OnCriticalError);
return endpointConfiguration;
});
#endregion
#region back-end-register-service
builder.ConfigureServices(services =>
{
services.AddSingleton<IExtract, ExtractOsiris>();
});
#endregion
return builder;
}
private static Task OnCriticalError(ICriticalErrorContext arg)
{
throw new NotImplementedException();
}
}
}
The Interface
using Newtonsoft.Json.Linq;
using NServiceBus;
using System;
using System.Threading.Tasks;
namespace Extractor
{
public interface IExtract
{
Task<JArray> Extract(string #object, DateTime deltaTime);
}
}
The handler
using System.Threading.Tasks;
using Messages;
using Newtonsoft.Json.Linq;
using NServiceBus;
namespace Extractor
{
#region back-end-handler
public class JobStartHandler : IHandleMessages<JobStartCommand>
{
private readonly IExtract extractor;
public JobStartHandler(IExtract extractor)
{
this.extractor = extractor;
}
public async Task Handle(JobStartCommand message, IMessageHandlerContext context)
{
Task<JArray> result = extractor.Extract("Medewerkers", message.DeltaTime);
await result;
JArray test = result.Result;
foreach (JObject x in test)
{
// send the object to be processed.
//await context.Send(new ProcessObjectCommand(x.ToString()));
}
}
}
#endregion
}
The implementation of the interface
using System;
using System.IO;
using System.Net;
using System.Threading.Tasks;
using Extractor;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using NServiceBus;
namespace ExtractorOsiris
{
public class ExtractOsiris : IExtract
{
private readonly ILogger logger;
public ExtractOsiris(ILogger<ExtractOsiris> logger)
{
this.logger = logger;
}
public Task<JArray> Extract(string #object, DateTime deltaTime)
{
logger.LogInformation($"getting {#object} for delta time {deltaTime}");
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create("https://xx.yy");
WebResponse response = request.GetResponse();
JObject temp = JObject.Load(new JsonTextReader(new StreamReader(response.GetResponseStream())));
return Task<JArray>.FromResult(temp["items"] as JArray);
}
}
}
I know the code ain't pretty, but it's pure quick and dirty testing code.

Answer 1

I cleaned out the offending interface from the code and still got the error on an interface that was not even there anymore. I removed the bin folder and build everything back up step by step. Stupid thing is, source control says I am back where I started, without changes. And it just works....
So must have bin something stupid with VS2019. Sorry to anyone who's time I wasted