Experimental Visual Studio Embedded Preview is now in main

[Chris Anderson (codemonkeychris)]

Progress on: #518

Thanks Hefaistos68 for the issue and the push to do something with their prototype of a solution :)

We merged the first phase of the Reactor Visual Studio embedded-preview extension. This adds a Reactor Preview tool window inside Visual Studio that launches a Reactor app through dotnet watch, talks to the devtools host, and attempts to embed the live WinUI surface directly into VS.

This is intentionally very rough — probably the roughest surface in the repo right now. Expect install friction, solution-load edge cases, DPI/HWND weirdness, blank-window bugs, and breaking changes while we harden it. Treat it as an experimental feedback vehicle, not a stable workflow yet.

How to install / test

The easiest path from a fresh checkout is to run:

 .\bootstrap.ps1

bootstrap.ps1 now builds and installs the local Reactor packages/templates and, when Visual Studio with the extension-development workload is available, attempts to build and install the VSIX as well.

For direct VSIX install/reinstall testing:

 pwsh -File src\vs-reactor\Reinstall-Vsix.ps1

Then open Visual Studio and use:

View → Other Windows → Reactor Preview

Docs and test checklist:

• User guide: docs/guide/vs-extension.md
• VSIX developer README: src/vs-reactor/README.md
• Manual smoke checklist: src/vs-reactor/TESTING.md

If you try it, please capture:

• VS version / architecture
• Windows version
• target app architecture / WinAppSDK version
• Reactor Preview output-pane logs
• whether the issue is install, launch, solution-load, DPI, reparenting, input, or hot reload related

Again: this is early and rough, but it’s the first end-to-end slice of the embedded Visual Studio preview direction.

[danielgruethling]

Wait so reactor gets a UI preview window that shows the WinUI surface while the framework itself is still unfinished and WinUI3 is still waiting on anything of a preview without having to run the full application while being released for a while now? Having to work around the heavily broken hot reload is really annoying. I might just switch to reactor just for this when it's more stable.

[saint4eva (saint4eva)]

Yes, give Reactor a try. And give some feedbacks also