Re-target .NET Core to net471, net 472

Question

My .Netcore 2.0 project can target net471. But when I upgraded to .NET 2.1, I can't retarget net471 or net472

Can I retarget in the latest version of .the NET core?

Severity Code Description Project File Line Suppression State
Error NU1202 Package Microsoft.AspNetCore.App 2.1.0 is not compatible with net471 (.NETFramework,Version=v4.7.1). Package Microsoft.AspNetCore.App 2.1.0 supports: netcoreapp2.1 (.NETCoreApp,Version=v2.1) 

and

Severity Code Description Project File Line Suppression State
Error NU1202 Package Microsoft.AspNetCore.App 2.1.0 is not compatible with net472 (.NETFramework,Version=v4.7.2). Package Microsoft.AspNetCore.App 2.1.0 supports: netcoreapp2.1 (.NETCoreApp,Version=v2.1) 

Favourite

In the most of cases, this is because the version of .NET Core SDK or Nuget is out of date. So try to update the version of Nuget – Marcin

Microsoft.AspNetCore.App is the new one, come with Asp.net core 2.1 – Favourite

What the message said. AspNetCore.App is a metapackage targeting .net core 2.1. It is used so we dont have to reference dozens of smaller ASP.NET Core assemblies. If you want to retarget to .NET Framework you have to REMOVE AspNetCore.App and add the single packages which you need, i.e. Microsoft.AspNetCore.Mvc – Fromm

Easiest way to do is, create a new empty ASP.NET Core project which targets .NET Framework 4.7.2, then copy the package references from it and replace the .AspNetCore.All (or .AspNetCore.All) package with these references as well as change the target platform in the csproj – Fromm

Thanks, @Fromm your solution works fine. – Favourite

Answer 1

It looks like Microsoft.AspNetCore.App and Microsoft.AspNetCore.All packages only work with the netcoreapp2.0 or netcoreapp2.1 version.

Wanting to target .NET Framework i.e. net471, net472, you have to remove these packages and manually add the references.

In my case, I removed Microsoft.AspNetCore.App and added references as below.

<PackageReference Include="Microsoft.AspNetCore" Version="2.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Hosting.WindowsServices" Version="2.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.1.1" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.1.1" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="2.1.1" />
<PackageReference Include="Microsoft.Extensions.Logging.EventLog" Version="2.1.1" />
<PackageReference Include="Microsoft.Extensions.Options" Version="2.1.1" />

Favourite

This solved my problem. I am targeting net48 and could not get it to work. From learn.microsoft.com/en-us/aspnet/core/migration/… I was given the impression that the reference to Microsoft.AspNetCore.App would work. – Lexicography

Answer 2

Hung Quach's answer is right 99% right. However I found it was missing two packages. So below is the full .csproj including the two missing project refs:

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

  <PropertyGroup>
    <TargetFramework>net472</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore" Version="2.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.CookiePolicy" Version="2.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Hosting.WindowsServices" Version="2.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.HttpsPolicy" Version="2.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.1.1" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="2.1.1" />
    <PackageReference Include="Microsoft.Extensions.Logging.EventLog" Version="2.1.1" />
    <PackageReference Include="Microsoft.Extensions.Options" Version="2.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.1.2" PrivateAssets="All" />
  </ItemGroup>

</Project>

Rivkarivkah