It's correct reference .NET Core from .NET Framework project?

Question

I have an ASP NET MVC project with net471 target framework but I found nuget reference to Microsoft.AspNetCore.* or Microsoft.EntityFrameworkCore.*

It's correct? What problems can it entail?

Answer 1

It depends. First, I'm not sure if you're using terminology correct. Do you have an ASP.NET MVC 5 project or an ASP.NET Core project? If the former, then yes, it's very much incorrect. If the latter, then no it's fine, depending on the ASP.NET Core version.

.NET Framework 4.7.1 implements .NET Standard 2.0, which .NET Core 2.2 is also compatible with. Therefore, you can include ASP.NET Core 2.2 packages in a .NET Framework 4.7.1 project. Despite the name, an ASP.NET Core web app doesn't have to actually run on .NET Core. However, ASP.NET Core 3.0 or EF Core 3.0 would not work because those depend on .NET Standard 2.1, which no version of .NET Framework implements (and probably never will).