Look, listen to a good friendly advice: stop torturing yourself and chasing out your users with that MDI nonsense. Nearly everyone discourages it, and Microsoft worked hard to phase this thing out. Finally, MDI was not included in WPF even though it remains in
, presumably for compatibility with legacy code, but highly discouraged even by Microsoft where this concept was created.
There are many robust conceptions; the simplest one is the tabbed UI based on
Question on using MDI windows in WPF
MDIContainer giving error
How to Create MDI Parent Window in WPF?