How does nuget detect framework version?

Question

My nuget package has dll:s for different .Net framework versions. One for CLR2 and one for CLR4.

net20/mylibrary.dll
net40/mylibrary.dll

This works fine when I use a package in e.g. .Net 3.5 and .Net 4 projects.

Sometimes I have projects which work with both .Net 3.5 and .Net 4. This is handled via 2 project configurations. In one case I build the .Net 4 version from the "Debug" configuration and the .Net 3.5 version from the "Release" configuration. Both of the configurations need to use net20 references.

My csproj file looks like this:

<PropertyGroup>
    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
    ...
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
    ...
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
    ...
</PropertyGroup>

nuget will always install the net40 assemblies which break the "Release" build.

Currently I manually change net40 to net20 in the .csproj file after install/update. Is there a way to avoid the edit?

Answer 1

Create a separate project for .net 4 and link the files into it.