.Net Plugin Architecture Not Working with Nuget

问题

I have a .Net Core 3.1 console application that loads plugins. One of my plugins connects to Sqlite and so it has a Nuget dependency on Microsoft.Data.Sqlite. However, I'm getting a missing DLL exception from the console app when loading/running the plugin because the following path doesn't exist:

MyConsoleApp\bin\x86\Debug\netcoreapp3.1\runtimes\win-x86\native\e_sqlite3.dll

I also have an MsTest project which tests this Sqlite plugin project. It does not have the same problem. Apparently the runtimes folder and contents will automatically exist if a Visual Studio project (1) is some kind of executable and (2) has a pertinent Nuget or project reference.

Following those rules, two of my three Visual Studio projects do not have the runtimes folder:

• The plugin has a Nuget dependency on Microsoft.Data.Sqlite, but does not have the runtimes folder because the plugin project is a DLL...not an executable.
• The MsTest project which tests the Sqlite plugin does have the runtimes folder and contents because (1) it it is a type of executable and (2) it has a project reference to the plugin project (which in turn references the Nuget package).
• The main console app is an executable, but (intentionally) doesn't have a project reference to the plugin. Thus it does not have the runtimes folder.

How do I solve this? As a hack I have simply copied the missing DLL into the output target directory for the console app.

Also, if I add a project reference from the console app to the plugin, this problem is solved. But, as stated, I don't want the console app to have project references to any plugins. Plugins should be discovered dynamically. I think fixing this may have something to do with creating a nuspec file. However, the documentation for nuspec files has no commentary about addressing this.

回答1:

.Net Plugin Architecture Not Working with Nuget

Just as you said that, the lib plugins project which references Microsoft.Data.Sqlite does not have the runtime folder and when an exe project reference the lib plugins project, the runtimes folder will be copied into the the exe project's output folder.

Solution

1) Since you do not want to reference the lib plugins project for the console project, you can just do a copy task in msbuild from the MsTest project's runtimes folder.

Write this target in the xxx.csproj file of Net Core 3.1 console application:

<Target Name="Copy_Runtimes" AfterTargets="Build">

        <ItemGroup>
            <CopyItems Include="..\MsTest\bin\Debug\xxx\runtimes\**\*.*" />
        </ItemGroup>

        <Copy SourceFiles="@(CopyItems)" DestinationFolder="$(OutputPath)runtimes\%(RecursiveDir)%(Filename)%(Extension)')"></Copy>
</Target>

2) Besides, you can also install the nuget package called sqlite in the net core 3.1 console application, and this package only contains the runtimes folder and does not include other com dlls for using.

It is actually a pure service package for providing runtimes folder.

You can install this package in your console project directly and if you are not satisfied with this, you can only try solution 1 to solve the issue.

来源：https://stackoverflow.com/questions/63155553/net-plugin-architecture-not-working-with-nuget