While trying to implement a MDI Application I found that the Windows.Forms
classes that implement this functionality don't actually use the WIN32 MDI
API.

Using Spy++ I found that the MdiClient class does not use the 'MDICLIENT'
window class. I also hooked up a Messagefilter to look at the MDI messages
send to the mdiclient, the only messages I saw were WM_MDISETMENU and
WM_MDIREFRESHMENU.

Can anyone confirm this or does anyone know why this was done?