BOOL CBCGPMDIFrameWnd::m_bCanConvertControlBarToMDIChild

protected

Tells whether docking control bars can be converted to MDI child windows.

If this flag is TRUE, the framework handles the conversion automatically when the user selects "Tabbed Document" menu item. The flag is protected and you need to explicitly enable this option either by setting m_bCanCovertControlBarToMDIChild in a constructor of a CBCGPMDIFrameWnd - derived class, or by overriding CanCovertControlBarToMDIChild().

The default value is FALSE.