Custom behavior is not parsing

[limeniye]

Related from: https://github.com/CommunityToolkit/WindowsCommunityToolkit/discussions/4927

States

• Create a simple project with the CommunityToolkit.WinUI.UI.Behaviors
• Add the following code:

public class ShowAttachedFlyoutBehavior
	: BehaviorBase<FrameworkElement>
{
	protected override bool Initialize()
	{
		var result = ShowAttachedFlyout();
		return result;
	}

	protected override bool Uninitialize()
	{
		HideAttachedFlyout();
		return true;
	}

	private bool ShowAttachedFlyout()
	{
		if (AssociatedObject == null)
		{
			return false;
		}
		FlyoutBase.ShowAttachedFlyout(AssociatedObject);
		return true;
	}

	private void HideAttachedFlyout()
	{
		FlyoutBase.GetAttachedFlyout(AssociatedObject).Hide();
	}
}

<Grid x:Name="AddNewGrid" ColumnDefinitions="70,Auto,20" Height="{Binding ElementName=NavigationPanel, Path=ActualHeight}">
	<FlyoutBase.AttachedFlyout>
		<MenuFlyout>
			<MenuFlyoutItem Text="UDP"/>
			<MenuFlyoutItem Text="TCP"/>
		</MenuFlyout>
	</FlyoutBase.AttachedFlyout>
	<i:Interaction.Behaviors>
		<core:EventTriggerBehavior EventName="Tapped" SourceObject="{Binding ElementName=AddNewGrid}">
			<behaviors:ShowAttachedFlyoutBehavior/>
		</core:EventTriggerBehavior>
	</i:Interaction.Behaviors>
	<TextBlock Grid.Column="1" Text="New" VerticalAlignment="Center"/>
</Grid>

• Deploy your application

Expectations

All should be without errors and warnings

Result

Parsing error

Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll
The text associated with this error code could not be found.

Option info

If you will remove the line <behaviors:ShowAttachedFlyoutBehavior/> the error will disappear.

Behaviors packages CommunityToolkit.WinUI.UI.Behaviors 7.1.2 / CommunityToolkit.WinUI.Behaviors 8.0.230907
Original post: unoplatform/uno#13145 (comment)
Visual Studio: 17.8.0 Preview 1.0 / Visual Studio 17.9.0 Preview 1.0
Repository:
https://github.com/limeniye/UnoCustomBehaviorParsingError

UnoCustomBehaviorParsingError-main.zip