Nuget package contentFiles not copied to .NET Core

问题:

I'm trying to extract content files from a Nuget package to a project referencing my package.

Based on Justin Emgarten's comment

Packages.config projects use the content folder

Project.json/PackageReference/NETCore SDK projects use the contentFiles folder

So ok great, I created a .NET Core 2.1 Console Application project and followed the NuGet ContentFiles Demystified blog post which was written in 2016 at the time of project.json but should still work nowadays.

I created an image at c:\dev\ContentFilesExample\contentFiles\any\any\images\dnf.png then created a c:\dev\ContentFilesExample\ContentFilesExample.nuspec file and copy pasted the content:

<?xml version="1.0"?>
<package>
    <metadata minClientVersion="3.3.0">
        <id>ContentFilesExample</id>
        <version>1.0.0</version>
        <authors>nuget</authors>    <!-- The NuGet team authored this package -->
        <owners>nuget</owners>      <!-- The NuGet team owns this package -->
        <requireLicenseAcceptance>false</requireLicenseAcceptance>
        <description>A content v2 example package.</description>
        <tags>contentv2 contentFiles</tags>
        <!-- Build actions for items in the contentFiles folder -->
        <contentFiles>
            <!-- Include Assets as Content -->
            <files include="**/images/*.*" buildAction="EmbeddedResource" />
        </contentFiles>
    </metadata>
</package>

Then I generated the Nuget package with the command nuget pack ContentFilesExample.nuspec and opened it using Nuget Package Explorer

Great my picture is there as expected.

And now the final non-working step. I install this Nuget package in my .NET Core 2.1 project but the image is missing. No trace of the image in the root directory of my project, neither in the obj folder nor in the bin folder.

I tried to close and re-open visual studio as stated in some comments somewhere but that didn't solve the issue.

I also tried to change my .NET Core project style to PackageReference but again, this didn't solve the issue

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>netcoreapp2.1</TargetFramework>
        <RestoreProjectStyle>PackageReference</RestoreProjectStyle>
    </PropertyGroup>

    <ItemGroup>
        <PackageReference Include="ContentFilesExample" Version="1.0.0" />
    </ItemGroup>

    <ItemGroup>
        <None Update="appsettings.json">
            <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
        </None>
    </ItemGroup>

</Project>

So what am I doing wrong? Are content files in Nuget packages really supported by .NET Core?

Thank you

回答1:

nupkg should have contentFiles/ directory:

Install to netcore project:

It won't be a loose file in the consuming project, it will be an EmbeddedResource when you build the project: