Using Unity instead of ASP.Net Core DI IServiceCollection

Question

More and more .NET Core libraries is bound to IServiceCollection. In example, I want to use HttpClientFactory described here in my NET Framework 4.7.1. desktop application. My application is using Unity IoC. I referenced Microsoft.Extensions.Http as NuGet.

But there is a problem: new ASP.Net Core components are bound to Microsoft DI framework for .NetCore - IServiceCollection. In example, registration of HttpClientFactory is here:

public void ConfigureServices(IServiceCollection services)
{
    services.AddHttpClient();
}

I was going deeper into MS code and wanted to manually register corresponding interfaces and classes to Unity. This is how services are registered by IServiceCollection:

services.TryAddTransient<HttpMessageHandlerBuilder, DefaultHttpMessageHandlerBuilder>();
services.TryAddSingleton<IHttpClientFactory, DefaultHttpClientFactory>();

This would be no problem to move this to Unity IoC, but I am stucked when I want to register DefaultHttpMessageHandlerBuilder and DefaultHttpClientFactory which have internal visibility. So they are not available for registration outside of MS code.

Do I have any chance how to resolve this situation?

Well, as you said, the two concrete types you are looking to use are internal, so that's that, you can't directly use them. Just wanted to add a thought: can you set up your Unity IOC so that it resolves IHttpClientFactory by in turn resolving IHttpClientFactory from the ASP.NET IServiceCollection? — p e p
I resolved this issue by using unity adapter for IServiceCollection: stackoverflow.com/a/51036884/245460 — Karel Kral

Karel Kral Karel Kral · Accepted Answer · 2018-06-26T07:10:04

Based on @davidfowl answer, I have used his second solution and completed code:

These packages need to be referenced from my project (snippet from .csproj):

 <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Http">
      <Version>2.1.1</Version>
    </PackageReference>
    <PackageReference Include="Unity.Microsoft.DependencyInjection">
      <Version>2.0.10</Version>
    </PackageReference>
  </ItemGroup>

And here is the test that services from ServiceCollection can be resolved from Unity container:

using System;
using System.Linq;
using System.Net.Http;
using Microsoft.Extensions.DependencyInjection;
using Unity;
using Unity.Microsoft.DependencyInjection;
using Xunit;

namespace FunctionalTests
{
    public class UnityWithHttpClientFactoryTest
    {

        /// <summary>
        /// Integration of Unity container with MS ServiceCollection test
        /// </summary>
        [Fact]
        public void HttpClientCanBeCreatedByUnity()
        {
            UnityContainer unityContainer = new UnityContainer();

            ServiceCollection serviceCollection = new ServiceCollection();
            serviceCollection.AddHttpClient("Google", (c) =>
            {
                c.BaseAddress = new Uri("https://google.com/");
            });
            serviceCollection.BuildServiceProvider(unityContainer);

            Assert.True(unityContainer.IsRegistered<IHttpClientFactory>());
            IHttpClientFactory clientFactory = unityContainer.Resolve<IHttpClientFactory>();
            HttpClient httpClient = clientFactory.CreateClient("Google");

            Assert.NotNull(httpClient);
            Assert.Equal("https://google.com/", httpClient.BaseAddress.ToString());

        }

    }
}

Using Unity instead of ASP.Net Core DI IServiceCollection

2 Answers