Re: need some class help
"RB" <NoMail@NoSpam> wrote in message
news:%23$24wndsKHA.4652@TK2MSFTNGP02.phx.gbl...
And exactly what is being compiled when (in the VStudio Class wizard )
when I
create a resource control variable of category "Control" and of type
"DerivedClass"
and the Control is owned by the FormViewClass? I.e. the DerivedClass has a
function
that is replacing the resource control's Base Class function but the
resource control is
owned by the FormViewClass or it's window ?
When you add a control variable the class wizard adds a line like this in
DoDataExchange
DDX_Control(pDX, IDC_LB_TOSEND, m_FormListBoxObj);
and this gets called during the dialog or formview initialization. This
line is responsible for all the magic. MFC is working hard for you to make
this happen. It intercepts all messages sent to the control, and passes
them to your derived class message map. If you don't add a handler for a
message, and/or if you handle it and call the base class, then the message
is passed on to the control's built in code. This lets you modify the
standard behavior of the control. The technique is called "subclassing" of
the control, a Windows term that has nothing to do with C++ classes. It's
done by hooking messages before they get to the control's code.
--
Scott McPhillips [VC++ MVP]