为什么添加Microsoft.Extensions.Logging原因无法加载文件或程序集System.Net.Http version = 4.2.0？

Question

I started getting from a new .Net 4.6.2 Unit Test project. It was really strange so I set out to reproduce with a simplified project which I've put on Github and attached. Unzip and run Nuget restore in VS. There are 2 commits. The first has it failing and the 2nd has it fixed after removing the " Microsoft.Extensions.Logging.Abstractions " and Microsoft.Extensions.Logging NuGet packages. Adding that package back in will cause the tests to fail.

Please help me understand this strange issue. Does it have something to do this package being from .Net Standard? System.Net.Http is coming from .NET Core + Platform Extensions, according to apisofnet , but I'm not using .Net Core.

What can I do continue using System.Net.Http version 4.0.0.0? Build output has: Unified primary reference "System.Net.Http, Version=4.2.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".

Update Note: I ran through this same exercise of removing Nuget packages from my first commit and the tests didn't pass, so all of this may be a red herring. The screenshots below show that I was successful one time anyways.

Update 2: I reproduced it with commits step by step: https://github.com/aligneddev/UseSystemNetHttpReferencing/commits/reproduce . I removed all packages, then after removing the last one Microsoft.Extensions.DependencyInjection.Abstractions - system.Net.http is missing build error. I then added in the reference with ReSharper and the unit test passes!

Last Update: downgrading to .Net 4.5.2 solves the problem as well. I don't really want to do that :-).

Answer 1

Adding binding redirection in app.config of UseSystemNetHttp.Test project fixes your issue:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Net.Http" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.2.0.0" newVersion="4.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
</configuration>