3.1 Relationships between the MFC MDI Classes
4.1 Relationships between HOOPS/ MFC GUI Integration Classes
CWinAppThe primary organizing object in the MFC framework is the CWinApp object. Each application has one and only one global instance of this object and all other objects are connected to it. CWinApp is derived from CWinThread, which manages the main event loop of the application. When an MFC-based application program (executable) is launched, the CWinApp object is created, initialized and its Run method is invoked. Application specific initialization and exit functionality are the responsibility of the CWinApp object.
CMDIFrameWnd
The CFrame object is a container for the applications user interface elements: pull down menus, push buttons (icons), and CView objects. As its name, 'frame', implies the CMDIFrameWnd object manages the layout of the application. When running in 8-bit mode, the CMDIFrameWnd object manages a color palette which may be shared by all attached CView objects.
CDocument
CDocument encapsulates the Document part of the Document/View paradigm. Application specific objects are typically connected to the CDocument object. Document objects are typically stored in files on the computer and this object has methods for handling file reading and saving.
CView
CView encapsulates the View part of the Document/View paradigm. Views are associated with CDoc objects. Views contain window 'panes' into which the application 'draws' the representation of the Document's data. There may be several views of a document but typically only one document per View. This means there may be several CView objects per CDocument object.