WinUI 3.0 roadmap - we need your input!

[jesbis]

WinUI 3.0

At the Microsoft Build conference in May 2019 we shared our plans for WinUI 3.0, which will greatly expand the scope of WinUI to include the full native Windows UI platform. This means that the full Xaml framework would be developed on GitHub and ship out of band as NuGet packages.

The WinUI roadmap is now up to date with the latest plans for WinUI 3.0:
https://github.com/microsoft/microsoft-ui-xaml/blob/master/docs/roadmap.md

You can also watch the Build 2019 conference session State of the Union: The Windows Presentation Platform for more details.

We'd love to hear what you think, and have some specific questions below.

How will this affect building Windows apps and components?

WinUI 3.0 will provide many benefits compared to the UWP Xaml framework, WPF, WinForms and MFC.

So, we want to make sure it's easy for everyone to use WinUI 3.0 in new and existing apps. There are a few ways we can approach this, and we'd love to hear your feedback on what areas we should focus on.

Our current thinking is:

Creating a new app

We plan to create new Visual Studio 2019 project templates for common languages (e.g. C# using .NET Core, standard C++17 using C++/WinRT) and app model + packaging (UWP + AppX, Win32 + MSIX).

What templates would interest you most?

The developer experience would be similar to current UWP apps.

Adding WinUI 3.0 to existing Win32 apps

WinUI 3.0 will include Xaml Islands, which let you use WinUI Xaml in your existing WPF, Windows Forms, and C++ Win32 applications.

The current version of Xaml Islands is only supported on Windows 10 May 2019 Update (1903), but the WinUI version should be backward-compatible to Creators Update (15063).

Were you aware of Xaml Islands for modernizing desktop apps?
Does this expanded backward-compatibility on Windows 10 make Xaml Islands more useful to you?

Updating your existing UWP Xaml app to WinUI 3.0

You'll have to update your app's target version to WinUI 3.0 to take advantage of it, similar to retargeting to a newer UWP SDK today.

We want to maximize compatibility between UWP Xaml and WinUI 3.0, but there will be some things to be aware of when updating.

1. Namespace update

The root namespace for Xaml, composition, and input APIs in WinUI will be different than the Windows UWP SDK root namespace:

Old namespace	New namespace (tentative)
Windows.UI.Xaml	Microsoft.UI.Xaml
Windows.UI.Composition	Microsoft.UI.Composition
Windows.UI.Input	Microsoft.UI.Input

We're exploring options for helping you automatically update namespaces when retargeting your UWP app to WinUI 3, at least for .NET apps.

Would it help if Visual Studio or another tool automatically updated namespaces for you?

2. Mixing UWP and WinUI Xaml components

The fastest path to releasing WinUI 3.0 would be to not support mixing:

• UWP Windows.UI.Xaml.UIElement and Windows.UI.Composition.Visual elements

with:

• WinUI 3.0 Microsoft.UI.Xaml.UIElement and Microsoft.UI.Composition.Visual elements

in the same app.

However, one of our biggest concerns is the compatibility issues and work that could create for existing UWP apps and component libraries, particularly if you're authoring or consuming UWP Xaml control libraries.
For example, existing versions of the Windows Community Toolkit wouldn't be usable in WinUI 3.0 apps, so both the Toolkit and any apps using it would need to update before using WinUI 3.0.

We hope that all UWP Xaml control libraries can be updated to WinUI 3.0, but we know that even in the best case it would take time for everyone to update.

How important to you is full compatibility between existing UWP Xaml components and WinUI 3.0 apps?

Do you create or use UWP Xaml control libraries or WinRT components that you couldn't easily recompile and update alongside app code?

What would be your preferred solution for using UWP Xaml components with WinUI 3?

General questions

1. What do you think about the overall 3.0 plan outlined above and in the roadmap? Would it enable you to use WinUI for your new and existing Windows apps?

2. What kind of apps would you be most excited to use WinUI 3.0 for? Creating a new Win32 app and packaging it with MSIX? Adding new views to a WPF app? Modernizing a C++ MFC app with Fluent UI?

[mdtauk]

These are my initial thoughts on the questions you asked in the issue content.

I come from a design and user perspective, with only a little development experience, who got very interested in Silverlight/Windows Phone 7 development back in the day who now feels a little burned.

What templates would interest you most?

I think before asking for a list of template ideas, there needs to be some kind of audit done of the biggest and most used apps in each framework, so WPF, UWP, WinForms, MFC etc.

Examine the "silhouette" of these apps and figure out the common UX scenarios.

Off the top of my head, there is:

• Main Menu (All frameworks)
• MDI (multiple documents in a single window) (MFC mostly)
• Tabs and Datagrid (WPF, WinForms, MFC)
• Ribbon (Win32 apps Office, 3ds max, paint, wordpad, File Explorer etc)
• System Tray Utilities (MFC, WinForms)
• Browsers
• Wizards (WPF, MFC)
• Complex MDI apps (Adobe software, Visual Studio)
• Media Players
• Data Visualisation LoB (WPF and Web)
• Social apps (React Native, PWA - Skype, Facebook, Twitter)

All or some of these could benefit from WinRT/UWP system integration with Notifications/Action Centre.

All these New Project templates should eschew the built in Windows.Xaml namespaces, WPF control theme, and WinForms visual styles in favour of new templates and visual styles which match the FabricWeb/Fluent control designs.

There should also be an easy way for devs with existing WPF and WinForms apps to add a WinUI 3.0 dependency which gives them the new control designs with a simple using statement or manifest entry

XAML Islands

As Xaml Islands becomes easier to make possible - replacing old webview controls, colour pickers, XAML based Dialogs could be as easy as a Add New... and choose a Dialog, or standard control which existing C# and C++ code can call into, and they have their own codebehind.

Modern app and page templates like Xbox Next apps, NavigationView, Master/Details, Hubs, Modern Ribbon, NavigationViewTop, and Pivot - could all be made available for all Windows Presentation Platforms - with XAML Islands in place and sample content.

Any of these scenarios which are not currently possible in UWP XAML, should be with controls and templates to make these easier.

Would it help if Visual Studio or another tool automatically updated namespaces for you?

It should be a question asked when someone opens their project on the latest version of Visual Studio with a current Windows 10 SDK. Press the button and it either replaces the name spaces and using, or flags them if it is not a control it is familiar with.

On new projects it should be the default, and the nuget package installed along with future versions of the Windows SDK.

What would be your preferred solution for using UWP components with WinUI 3?

As with the automatic updating answer, New pages and projects should include it by default, and a message asking if they want to Automatically move to WinUI | Add ToDo comments to update namespaces | Do not move to WinUI.

What kind of apps would you be most excited to use WinUI 3.0 for?

As a user I want all apps running on Windows to share a common UI and UX no matter what framework was used.

I want apps to be installed without messing with the registry and leaving junk behind. (so Centennial)

I want all the apps to be installable from within the store, or from a Centennial type installer. Virtualise the System and Windows folders for every app.

Modernizing a C++ MFC app with Fluent UI?

Acrylic should be available to WPF, WinForms, and MFC apps, and included in default new templates via a WinUI 3.0 dependency or manifest. CommonControls and window styles should use Acrylic and extended titlebars (which can be overridden to go back to the current defaults)

Microsoft's Win32 non UWP apps need to all be recompiled with WinUI 3.0 so they all use Acrylic window frames, main menus, ThemeShadows, Context Menus, Text Fields, Progress Bars etc.

And then existing apps need a simple solution to drop in WinUI 3.0+ which then updates the looks of all the controls - or the ability to apply it selectively one dialog at a time, until the entire UI is updated.

[paulio]

re: namespaces, I would expect them to just change based on the target even it requires conditional namespaces.

[simonferquel]

Here are my answers:

Creating a new app

What templates would interest you most?

• I'd love to see c++/winRT win32+xaml and .net core+xaml first there, UWP templates coming second, packaged win32 app should not come as a template, as current app package templates should just work as they already do with current win32/.Net apps.
• Additionaly, I'd love to see item templates like "New XAML Window" with boiler-plate code to show it in an existing win32 or .net core App application (e.g.: making existing systray app à la Docker Desktop, able to show a new top level Xaml Window)

Adding WinUI 3.0 to existing Win32 apps

• non-backward compatibility is the exact reason why I never used xaml islands on a real project (used it for fun on personal stuff though). Decoupling the UI framework from the Windows API is one of the greatest thing announced with the WinUI 3.0 roadmap (alongside the ability for non-packaged/non-uwp targetting apps to leverage it)

Updating your existing UWP Xaml app to WinUI 3.0

It might sound harsh, but I feel like UWP xaml app are a niche (since the drop of windows phone, there is no more traction toward UWP as a target platform), and even if tooling/interop would be nice to have, I don't think it should be the main focus for WinUI 3.0.
So both namespace update tooling (which might be actually done using a global find and replace) and mixing UWP xaml and WinUI xaml do not feel critical to me.

[simonferquel]

Also, just want to mention that this is a very welcome move, and having the whole UI framework open source on Github is awesome! Thanks a lot for doing this!

[GeertvanHorrik]

First of all, this is a great move! Unfortunately I cannot neglect the fact that I feel a bit hurt by the way Microsoft has dealt with the few last developers on their platform. At the moment I only use UWP for consumer-facing apps because:

1. WPF is way more mature than WinUI (validation, existing controls, etc), so for enterprise WPF is a better fit
2. UWP is great for multiple device categories (mobile, tablet, desktop, etc), that's where the consumers are at

It's great to see point 1 could be tackled with WinUI, so that makes me enthusiastic about the progress for WinUI. Unfortunately 2 is no longer applicable (no more cool devices, just desktops). It makes one wonder, at the time this stuff ships (1 year from now earliest?), what would developers need at that stage.

I think the consumer stuff is no longer part of the equation, that ship has sailed with the retrenchment "strategy". So the only thing it could be good for are enterprise apps.

In general, I would be more interested in a good migration strategy from WPF to WinUI to try and migrate our massive WPF code-base to Windows 10. The downside of having to update consumer-facing apps (currently UWP) is that they highly depend on external component developers (e.g. win toolkit, etc). I think there is no viable option to update these anymore since most developers (I know of) lost interest in consumer / windows client development.

Answers to the questions

Creating a new app

What templates would interest you most?

I would love to see .net core / xaml / C# here, since I think that's the most used language combination available. But maybe a migration template would be better here (try to get everyone on board as quickly as possible, the longer it takes, the more painful it will get).

Adding WinUI 3.0 to existing Win32 apps

I think this is extremely nice, and we would use this a lot (but realistically, this is at least a year away since enterprise customers are still on Windows 7, even when MS support ends, companies will be on Windows 7). Then we can slowly migrate WPF to WinUI 3.

Were you aware of Xaml Islands for modernizing desktop apps?

Yes, but too many customers are (or were) on Windows 7, so it was not an option for enterprise devs. And for consumers you could just use UWP anyway.

Does this expanded backward-compatibility on Windows 10 make Xaml Islands more useful to you?

It's a good start because at the time this stuff ships, it would work on all supported versions of Windows 10 in the enterprise.

Updating your existing UWP Xaml app to WinUI 3.0

Consumer apps for MS are over, all because of the choices MS made, there is no more room for this. I would just skip this whole option and forget about it. It's sad because I put thousands of hours into UWP apps, but I think we need to make this death quick to make it less painful.

The whole promised story was always up-to-date, support all devices. I think we all know what way that promise went.

Would it help if Visual Studio or another tool automatically updated namespaces for you?

If it's just namespaces, a search / replace should do the trick as well.

How important to you is full compatibility between existing UWP Xaml components and WinUI 3.0 apps?

No longer important, I am willing to take the loss of thousands of hours of development, there are no users left anyway.

Do you create or use UWP Xaml control libraries or WinRT components that you couldn't easily recompile and update alongside app code?

Nope.

What would be your preferred solution for using UWP components with WinUI 3?

UWP Islands (sort of hosted components)

General

What do you think about the overall 3.0 plan outlined above and in the roadmap? Would it enable you to use WinUI for your new and existing Windows apps?

It probably needs some maturing, but I see myself using this stuff in 1 - 2 years for enterprise development. Depending on how hard it is to migrate, we will either choose WinUI or web (depending on how Windows itself "evolves").

What kind of apps would you be most excited to use WinUI 3.0 for? Creating a new Win32 app and packaging it with MSIX? Adding new views to a WPF app? Modernizing a C++ MFC app with Fluent UI?

Probably just adding new views to a WPF app and slowly start migrating.