How to enable auto-update with AppInstaller for MSIX Packages?

[LegendaryBlair]

Description

When publishing a MSIX package for a WinAppSDK app, the auto-update feature does not work as expected. Despite setting the update frequency to 'Every time the application runs' in Visual Studio, the app does not check for updates automatically and requires manual intervention.

Related issues

#1067
#3021

[LegendaryBlair]

Root cause

The issue is caused by the default appInstaller schema version generated by Visual Studio, i.e., http://schemas.microsoft.com/appx/appinstaller/2017/2, which does not support the ShowPrompt or UpdateBlocksActivation attributes needed for the desired auto-update behavior.

Solution

1. Add the property <GenerateAppInstallerFile>True</GenerateAppInstallerFile> to the wapProj to generate the .appInstaller file.
2. Manually update the .appInstaller file to use the schema http://schemas.microsoft.com/appx/appinstaller/2021.
3. Set the ShowPrompt attribute to true and UpdateBlocksActivation to true in the OnLaunch element, like so:
   <OnLaunch HoursBetweenUpdateChecks="0" ShowPrompt="true" UpdateBlocksActivation="true"/>.
4. Upload the updated .appInstaller file and corresponding package to the hosting website.

References: App Installer File Versioning