Ability to install .NET Framework 3.5

[silasary]

Description:
The windows-2022 runner image doesn't ship with Framework 3.5 anymore, and workflows that require it fail on the new runner.

As such, it would be nice to be able to install Framework 3.5 with setup-dotnet

Justification:
Builds started failing on windows-2022, and I had to roll back to windows-2019. This is not ideal, and won't last forever.

Are you willing to submit a PR?
If I have to, but I wouldn't know where to start.

[dmitry-shibanov]

Hello @silasary. Thank you for your report. We'll investigate the feature request.

[EivindAntonsen]

@dmitry-shibanov What about more recent framework versions, such as 4.7.2?

[teo-tsirpanis]

@EivindAntonsen Windows Server 2022 comes with .NET Framework 4.8, which is compatible with all previous versions of .NET Framework.

[nogic1008]

@silasary It should be enabled in Windows Features.
https://learn.microsoft.com/dotnet/framework/install/dotnet-35-windows

On powershell:

Enable-WindowsOptionalFeature -Online -FeatureName "NetFx3"

[MrMTaylor]

I had this issue but I've been able to use the Setup .NET Core SDK Action to install .Net 3.5.

- name: Add .Net 3.5 Framework
  uses: actions/setup-dotnet@v3
  with:
    dotnet-version: '3.1.x'

I can then use dotnet --list-sdks to confirm:

[wasabii]

I had this issue but I've been able to use the Setup .NET Core SDK Action to install .Net 3.5.

- name: Add .Net 3.5 Framework
  uses: actions/setup-dotnet@v3
  with:
    dotnet-version: '3.1.x'

I can then use dotnet --list-sdks to confirm:

That isn't .net framework 3.5