Copy the nuget content folder to project output folder - nuget-package

Question

I have created a nuget package with this structure:
NugetName/lib/net/*.dll
NugetName/contentFiles/A/*.dll
NugetName/contentFiles/B/*.dll
> <?xml version="1.0" encoding="utf-8"?> <package
> xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
> <metadata>
> <id>..</id>
> <version>1.0.0.22</version>
> <title>...</title>
> <authors>...</authors>
> <owners>..</owners>
> <requireLicenseAcceptance>false</requireLicenseAcceptance>
> <description>...</description>
> <contentFiles>
> <files include="contentFiles\A" buildAction="content" copyToOutput="true" flatten="true" />
> <files include="contentFiles\B" buildAction="content" copyToOutput="true" flatten="true" />
> </contentFiles>
> </metadata>
> <files>
> <file src="Build\Debug\*.dll" target="lib\net\" />
> <file src="Build\Debug\A\*.dll" target="contentFiles\A" />
> <file src="Build\Debug\B\*.dll" target="contentFiles\B" />
> </files>
> </package>
And now, I need to copy the folders A and B into the project's output folder, but it does not do that!
After installing the nuget package, only the NugetName/lib/net/*.dll files are copied, but A and B are not!

Answer 1

After testing the different ways I came up with this solution.
First, I sent the dll files into the Build folder instead of the content folder.
<files>
<file src="Build\Debug\*.*" target="lib\net\" />
<file src="Build\Debug\A\*.dll" target="build\A" />
<file src="Build\Debug\B\*.dll" target="build\B" />
<file src="MyTargetFile.targets" target="build\MyTargetFile.targets" />
</files>
Then, I created a target file in the Build folder.
This is the new structure of my nuget package:
•Build
•A
•*.dll
•B
•*.dll
•MyTargetFile.target
•lib
• net
•*.dll
In the target file I defined how to copy the folder by MsBuild:
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<ItemGroup>
<NativeLibs Include="$(MSBuildThisFileDirectory)**\*.dll" />
<None Include="#(NativeLibs)">
<Link>%(RecursiveDir)%(FileName)%(Extension)</Link>
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</None>
</ItemGroup>
</Project>
Finally I created the new nuget package and installed it, and when I built the project, folders A and B are copied into the output folder.