.NET Standard 2.1 support on Universal Windows Platform

[YZahringer]

Regarding the support of .NET Standard 2.1 in UWP projects, it is written that it will be supported in the upcoming version.

This means that there will be the same problem as with the .NET Standard 2.0 version and that we will not be able to target older versions of Windows 10? .NET Standard 2.0 requires as min target version Windows 10 Fall Creators Update 16299.

This is a big problem for my projects and backward compatibility. I can't remove support for older versions of Windows 10, especially LTSC editions. This means that my projects are blocked in .NET Standard 1.4 and it also blocks any dependency updates:

• Xamarin.Forms 2.5 because version >=3.0 requires .NET Standard 2.0
• Microsoft.EntityFrameworkCore 1.1 because version >=2.0 requires .NET Standard 2.0
• .NET Core 1.1 because version >=2.0 requires .NET Standard 2.0

I can't ask my users to have the latest version installed, especially in business applications and Windows LTSC editions. I have to wait several years before removing the support of an old version.

Is it planned to continue support the min target version 16299 of UWP projects with .NET Standard 2.1? I understand the constraints, but with Xcode I can still min target iOS 7 and with Android I can still min target 4.4 KitKat, still with the latest version of frameworks. And with Windows I can only support the latest version? That doesn't make much sense.

[YZahringer]

• https://developercommunity.visualstudio.com/content/problem/748346/uwp-app-dotnet-core-3-and-ef-core-3-problem.html
• I cannot install EFCore 3.0 in UWP project  efcore#18011
• EF Core 3.1 to target .NET Standard 2.0 efcore#18141

[richlander]

I'm one of the people working on this. We're still working on our .NET 5 plan, which includes Xamarin and UWP. Our intention is to enable UWP apps to use .NET Core, which will resolve this request. We'll have more to share when we get through our planning process.

[YZahringer]

@richlander thank you for the answer. It is planned to wait for the release of .NET 5 to have support for .NET Standard 2.1 in UWP? or is it the resolution of the dependency between the Windows build number and the version of .NET Standard that may be resolved with .NET 5?

In my opinion, the version of .NET Standard supported in a UWP application should not depend on the version/minTarget of Windows.

[KPixel]

@YZahringer As you can read on the blog post announcing .NET 5, all platforms will share the same runtime. So, they will all get the same new features more or less at the same time.

The more tricky question is: The UWP SDK will get these new features when a new version of Windows is released. We know that the current cadence is every March & September.
Considering that .NET 5 will be released in November 2020, does that mean that UWP will have to wait for March 2021 to get that update?

So, no .NET Standard 2.1 before March 2021? (That seems really late)
I was hoping that we would get it at the 20H1 update (in March 2020)... But if not, at least 20H2 would be better.

[shlitzi]

What the fuck?????

[Happypig375]

@shlitzi Care to elaborate?

[joperezr]

@shlitzi let's try to be civil, if you have specific feedback we will be more than happy to help out or answer questions. Please review the COC.

[YZahringer]

No mention of UWP in the .NET 5 Preview 1 announcement and Unifying .NET 5 blog post

[Happypig375]

@YZahringer
dotnet/designs#92 (comment)

@terrajobst:

@Perksey

There hasn't been much mention of UWP. In earlier revisions it seems it was touched upon, but later removed. Perhaps this can be detailed a little bit (perhaps in the FAQ section) as I have no idea how to use .NET Native with WinRT/UWP APIs in the current state of the proposal.

It was removed because the plan for UWP is still under heavy construction. We'll release a new design proposal once they are ready, but meanwhile we have to make progress for the platforms we already have a plan for.
We've talked with the Windows folks how this will work and we assume that using net5.0-windows will generally work for UWP as well. However, I expect that in contrast to WinForms/WPF UWP projects will likely use a version number (because of the WinRT bindings, which makes UWP similar to iOS/Android).
I would like to avoid net5.0-uwp because it would mean that unless we invent crazy TFM rules, code targeting net5.0-windows wouldn't be able to reference net5.0-uwp (and vice versa).

[terrycox]

If UWP is compatible with .NET Core 3, I assume I can put non-UI pieces such as viewmodels and services in a .NET Core 3 library and access from a UWP app?