Creating an Razor Class Library with Framework Reference to Microsoft.AspNetCore.App

[TwentyFourMinutes]

Describe the bug

I am trying to put some of my Controllers and Views of my ASP.Net Core 3 pre-release 9 MVC Project in a different Project. Therefor I went with an Razor Class Library since as the documentation says:

Razor views, pages, controllers, page models, Razor components, View components, and data models can be built into a Razor class library (RCL).

So I went ahead and created a RCL Project which looks something like the following:

<Project Sdk="Microsoft.NET.Sdk.Razor">
  <PropertyGroup>
    <TargetFramework>netstandard2.1</TargetFramework>
    <RazorLangVersion>3.0</RazorLangVersion>
  </PropertyGroup>

  <ItemGroup>
    <FrameworkReference Include="Microsoft.AspNetCore.App" />
  </ItemGroup>
</Project>

I included the FrameworkReference instead of a PackageReference for the Microsoft.AspNetCore.App since the following issue tells me so. #3756

But this leaves me with the following error:

The FrameworkReference 'Microsoft.AspNetCore.App' was not recognized

[pranavkm]

You'll need a TargetFramework of netcoreapp3.0. Does changing the tfm fix the issue?

[TwentyFourMinutes]

Well if I use netcoreapp3.0 it resolves the dependency issues, but other errors occur.

I am not sure what the reason for this is...

[TwentyFourMinutes]

Also if it is the case that netcoreapp3.0 is the only possible TargetFramework, the template for RazorClassLibraries should be updated. They currently use netstandard2.0.

[TwentyFourMinutes]

For anyone else interested and having the same issue, you need to add this attribute <AddRazorSupportForMvc>true</AddRazorSupportForMvc> to your .csproj of the RCL.