Windows forms had a property win1.Handle which, if I recall, returns the handle of the main window handle?
Is there an equivalent way to get the handle of a WPF Wind
If you want window handles for ALL of your application's Windows for some reason, you can use the Application.Windows property to get at all the Windows and then use WindowInteropHandler to get at their handles as you have already demonstrated.
Window
Application.Windows
WindowInteropHandler