This project is for framework package only, and the Microsoft.UI.Xaml.pri is picked up by the framework package.

Allow single URI to access Compact.xaml from both framework package and nuget package

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="ms-appx:///Microsoft.UI.Xaml/DensityStyles/Compact.xaml"/> </ResourceDictionary.MergedDictionaries> </ResourceDictionary>