Windows UI (WinUI) 3 Preview 5 and Project Reunion 0.5 preview – Upgrade today

Ok, just a quick summary post – Windows UI 3.0 and Project Reunion 0.5 preview has just shipped. The most notable change is that WinUI now falls under Project Reunion with changes to namespace, packages and the Visual Studio extension.


Here’s a quick summary of getting the latest bits:

  • Start by removing the WinUI3 extension from Visual Studio – go to Extensions, Manage Extensions from the menu. Look in the list of installed extensions and click the Uninstall button against the WinUI 3 Project Templates item.
  • Next, search for “reunion” or “project reunion” and click the Download (I’m not sure why this says Download instead of Install…) button against the Project Reunion (Preview) item.
  • Once the Project Reunion (Preview) item has been downloaded and installed, you’ll need to close and allow the VSIX to run.

New Application

Creating a new application is the same process as with earlier WinUI previews – select one of the WinUI / Project Reunion templates to create a new project.

The project templates are designed to ensure you have all the right dependencies and starting files so that you can start building your application.

You can see from this image that all the dependencies now start with Microsoft.ProjectReunion prefix. According to Microsoft this naming will continue through the official release of WinUI 3.0 but should be changed prior to 1.0 shipping of Project Reunion.

Existing Applications

Upgrading existing applications is relatively easy – you just need to remove the old WinUI nuget package references and add in the new Project Reunion WinUI package.

Note that whilst a new application includes two additional Project Reunion packages, these aren’t required if you just want to use WinUI. However, it is noted that over the coming months more features will start to roll out as part of Project Reunion. If you include all the Project Reunion packages, you’ll automatically get these features simply by updating to the latest package versions (at least that’s the theory!).

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