WPF does not support MDI. Finally Microsoft decided to trash this garbage.
Here is the idea: who needs MDI, ever? Why torturing yourself and scaring off your users?
Do yourself a great favor: do not use MDI at all. You can do much easier to implement design without it, with much better quality. MDI is highly discouraged even by Microsoft, in fact, Microsoft dropped it out of WPF and will hardly support it. More importantly, you will scare off all your users if you use MDI. Just don't.
See:
http://en.wikipedia.org/wiki/Multiple_document_interface#Disadvantages[
^].
See also my past answers:
Question on using MDI windows in WPF[
^],
MDIContainer giving error[
^].
This is not MDI but the author of the article just called it MDI. In fact, this is not MDI but something much better:
Tabbed MDI in WPF[
^].
Now, what about forms? No, there are no forms in WPF, there are "windows". Forms there are in the
System.Windows.Forms library, but you cannot use them in WPF in any simple way. However, you can use some
System.Windows.Forms controls in WPF:
https://msdn.microsoft.com/en-us/library/ms751761%28v=vs.110%29.aspx[
^].
I won't recommend going this way either. If you use WPF, better develop everything in WPF, unless you have some ugly and compelling reason to utilize some Forms components.
—SA
Submit an article or tip