Create a new WinUI 3 and Uno Platform app

Uno Platform apps can be created in both UWP-compatible (Windows.UI.Xaml, also known as WUX) and WinUI 3-compatible (Microsoft.UI.Xaml, also known as MUX) flavors. In the latter case, you can use the latest features of .NET 5 and WindowsAppSDK (formerly known as "Project Reunion") for WinUI 3 Desktop apps. This article takes you through the steps of creating a WinUI 3-flavored Uno Platform app and running the app with WindowsAppSDK for Desktop.

Prerequisites

Set up your environment

  1. Install the Uno Platform dotnet templates. From a command-line prompt, run the following command:
    dotnet new -i Uno.ProjectTemplates.Dotnet
    

Create a new app

  1. Create a folder for your app.
  2. From a command-line prompt at that folder location, run the following command:
    dotnet new unoapp-winui -o MyUnoApp
    
  3. Open the solution file you created.
  4. UI Tooling features (Live Visual Tree, Live Property Explorer, and Hot Reload) for WinUI 3 need to be enabled in Visual Studio as a Preview Feature. Navigate to Tools -> Options -> Environment -> Preview Features and toggle "Enable UI Debugging Tooling for WinUI 3 Projects". Preview Feature screenshot
  5. To debug the WinUI 3 Desktop project, set [MyAppName].Windows.Package as the startup project, set the Solution Platform to x86, and run the application.

Further reading