https://learn.microsoft.com/en-us/uwp/api/windows.ui.xaml.dependencyobject.registerpropertychangedcallback?view=winrt-28000
DependencyObject.RegisterPropertyChangedCallback Method (Windows.UI.Xaml) - Windows apps |...
Registers a notification function for listening to changes to a specific DependencyProperty on this DependencyObject instance.
methodwindowsuixamlapps