https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.controls.primitives.flyoutbase.isopen?view=windows-app-sdk-1.8
FlyoutBase.IsOpen Property (Microsoft.UI.Xaml.Controls.Primitives) - Windows App SDK | Microsoft...
Gets a value that indicates whether the flyout is open.
windows appisopenpropertymicrosoftui