How to pack an x86 / x64 specific C++/CLI DLL with Nuget? - nuget

Question

I have a C++/CLI DLL that interfaces a third party native DLL. I want to pack this as Nuget.
I followed this official MS guide, this blog post and read through this other question.
So here is what I did:
First, I created the proper nuspec file:
<?xml version="1.0"?>
<package >
<metadata>
<id>CPlusPlusNativeIFace</id>
<version>1.0.4</version>
<title>CPlusPlusNativeIFace</title>
<authors>Jens Rabe</authors>
<owners>Who owns that</owners>
<requireLicenseAcceptance>false</requireLicenseAcceptance>
<description>A DLL that makes a native third-party DLL available to .net</description>
<releaseNotes>foo</releaseNotes>
<copyright>errm...</copyright>
<tags>foo bar</tags>
</metadata>
<files>
<file src="..\Release\**" target="runtimes/win-x86/lib/net461" />
<file src="..\x64\Release\**" target="runtimes/win-x64/lib/net461" />
<file src="DummyAny\**" target="ref\net461" />
</files>
</package>
Then I compiled the DLL for Release x86 and Release X64. Then I created the DummyAny folder, copied the contents of the x86 one in, and used the corflags utility like in Links 2 and 3 to strip the 32 bit flag.
When I now nuget pack and nuget add, and try to reference that package in another project, I always get:
Could not install package 'CPlusPlusNativeIFace 1.0.4'. You are trying to install this package into a project that targets '.NETFramework,Version=v4.6.1', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.
I double checked that the files are right:
I have the x86 stuff in runtimes/win-x86/lib/net461
I have the x64 stuff in runtimes/win-x64/lib/net461
I have a ref/net461 folder with the manipulated dll in
But I still can't load the package.
I also tried putting the CPU specific DLLs into runtimes/win-x86/native and runtimes/win-x64/native to no avail.
What else am I missing? Does that not work for C++/CLI projects built against .net Framework?

Answer 1

Turned out that the official MS documentation was not usable here.
This question was/is listed as "related" here and the accepted answer there made it work for me. I used the example project on Github as a reference.
So here is how I got it to work:
Opened the project properties, went to Configuration Properties / General, selected All Configurations and All Platforms, and as Output Directory, I specified: $(ProjectDir)bin\$(Platform)\$(Configuration)\
Rebuilt the project for x86 and x64 in Release mode
Adapted the Nuspec to be like this:
<?xml version="1.0"?>
<package >
<metadata>
<id>CPlusPlusNativeIFace</id>
<version>1.0.5</version>
<title>Third Party Proxy</title>
<authors>Jens Rabe</authors>
<owners>foo</owners>
<requireLicenseAcceptance>false</requireLicenseAcceptance>
<description>bar</description>
<releaseNotes>Further experimenting with nuget</releaseNotes>
<copyright>baz moo</copyright>
<tags>quux bletch</tags>
</metadata>
<files>
<file src="bin\Win32\Release\**" target="build\x86" />
<file src="bin\x64\Release\**" target="build\x64" />
<file src="bin\Win32\Release\**" target="lib\net461" />
<file src="CPlusPlusNativeIFace.props" target="build\net461" />
</files>
</package>
Added a CPlusPlusNativeIFace.props which contains the following:
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<ItemGroup>
<Reference Include="CPlusPlusNativeIFace" Condition="'$(Platform)' == 'x86'">
<HintPath>$(MSBuildThisFileDirectory)..\x86\CPlusPlusNativeIFace.dll</HintPath>
</Reference>
<Reference Include="CPlusPlusNativeIFace" Condition="'$(Platform)' == 'x64'">
<HintPath>$(MSBuildThisFileDirectory)..\x64\CPlusPlusNativeIFace.dll</HintPath>
</Reference>
</ItemGroup>
</Project>
Now I can do nuget pack CPlusPlusNativeIFace.nuspec and I get a Nuget package that installs correctly.