Assuming we had an Animal enum type and we wanted the user to pick one of the available names, here is the XAML syntax that allows us to create a ComboBox and display all Animal values, directly from XAML and with no code-behind:

<ComboBox
    xmlns:dev="using:DevWinUI"
    xmlns:enums="using:MyApplication.Enums"
    ItemsSource="{dev:EnumValues Type=enums:Animal}"
    SelectedIndex="0"/>

Demo

you can run demo and see this feature.