Multitargeting .NET Standard 2.0 missing some framework libraries

Question

Had a working ASP.NET Core using a .NET Standard DLL I wrote. I'd like to use TransactionScope in my DLL now, but getting this issue:

.NET Standard and .NET Core 2.0 both recognize System.Transactions, but .NET Framework 4.6.1 is giving an error and won't compile with MSBuild. Visual Studio 2017 offers the following helpful information:

I cannot seem to find a way to force the project to recognize System.Transactions.dll from my system's Framework/Framework64 folders.

Yes, I can use dotnet build to compile the .NET Core version, but that's not what I want... I want to be able to compile for .NET 4.6.1, too.

Answer 1

You need to add a framework referenced conditioned on the target framework.

Add this to your csproj file:

<ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">
  <Reference Include="System.Transactions" />
</ItemGroup>