Only include wanted content files in NuGet package - nuget

Question

I am building a nuget package from a c# class library project.
The class library itself has files that are marked as build action=content and I can't change this.
I don't want these content files in the nuget package. If I am using an empty files tag, these content files are not included.
<?xml version="1.0"?>
<package >
<metadata>
<id>$id$</id>
<version>$version$</version>
<title>$title$</title>
<authors>$author$</authors>
<owners>$author$</owners>
...
</metadata>
<files />
</package>
However, if I add at least on other file to my package like this
<?xml version="1.0"?>
<package >
<metadata>
<id>$id$</id>
<version>$version$</version>
<title>$title$</title>
<authors>$author$</authors>
<owners>$author$</owners>
...
</metadata>
<files>
<file src="source/path.dll" target="lib\net45\" />
</files>
</package>
every file marked as content in my project is included in my package, too.
Is there a way to avoid this?

Answer 1

Put this to the end of the .csproj file:
<ItemGroup>
<Content Update="#(Content)" Pack="false" />
</ItemGroup>
This will make every "build action=content" get excluded from the nuget.
Those "build action=content" entries will be actually <Content> Items in the MsBuild project - you could see them in the old .csproj format. (In the new SDK style format, by default, the project files are automatically included based on file extension; so probably you won't see the <Content> entries).
The code above updates every <Content> entry - which already exist when reaching that code (thus it should be at the end of the .csproj) - to be excluded from nuget pack