Normally, MDI parents are not designed to show anything except one window (in terms of raw Windows API) called "MDI client" used as a client area for all MDI Children, and nothing else. Here is what it is:
http://msdn.microsoft.com/en-us/library/system.windows.forms.mdiclient.aspx[
^].
It's pretty difficult to show anything else in it, and of course, it is not designed to hold any controls other than forms acting as MDI children.
That said,
MDI UI is just not good enough. 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. Please see:
http://en.wikipedia.org/wiki/Multiple_document_interface#Disadvantages[
^],
How to Create MDI Parent Window in WPF?[
^].
I can explain what to do instead. Please see my past answers:
How to Create MDI Parent Window in WPF? [
Solution 2],
Question on using MDI windows in WPF[
^],
MDIContainer giving error[
^],
How to set child forms maximized, last childform minimized[
^].
—SA
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