Привязка Win UI3 к AutoSuggestBox в MVVM

Сначала установите следующий пакет nuget

https://www.nuget.org/packages/Microsoft.Xaml.Behaviors.WinUI.Managed

тогда вы можете использовать Interaction и связать свой метод (из модели представления) в своем xaml

<AutoSuggestBox x:Name = "Control2" PlaceholderText = "Type a control name"
        TextChanged = "SearchBox_TextChanged" QueryIcon = "Find" Width = "300" HorizontalAlignment = "Left">
        <i:Interaction.Behaviors>
            <ic:EventTriggerBehavior EventName = "QuerySubmitted">
                <ic:EventTriggerBehavior.Actions>
                    <ic:InvokeCommandAction Command = "{x:Bind ViewModel.SearchBox_QuerySubmitted}" />
                </ic:EventTriggerBehavior.Actions>
            </ic:EventTriggerBehavior>
            <ic:EventTriggerBehavior EventName = "SuggestionChosen">
                <ic:EventTriggerBehavior.Actions>
                    <ic:InvokeCommandAction Command = "{x:Bind ViewModel.SearchBox_SuggestionChosen}" />
                </ic:EventTriggerBehavior.Actions>
            </ic:EventTriggerBehavior>
        </i:Interaction.Behaviors>
</AutoSuggestBox>

и csharp:

public void SearchBox_QuerySubmitted(AutoSuggestBoxQuerySubmittedEventArgs args)
{

}

public void SearchBox_SuggestionChosen(AutoSuggestBoxSuggestionChosenEventArgs args)
{

}