1.00 1.50
WINDOWS
kbprg
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The information in this article applies to:
The Microsoft Foundation Classes (MFC) included with:
- Microsoft Visual C++ for Windows, versions 1.0 and 1.5
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SUMMARY
=======
The VBX emulation layer provided by MFC will not send an event notification
unless the event has been registered. However, it might be desirable to
provide handling for non-registered VBX events. This could be used for
providing diagnostic information for all events that a VBX dispatches which
aren't handled by an application.
MORE INFORMATION
================
When a VBX event occurs MFC will search through all registered
events (registered using AfxRegisterVBEvent) to find the notification
code for the particular event which occurred. If the event has not
been registered then MFC will look for a default event. This event
is called: "Default VBEvent". If you register this event then the
VBX emulation layer will send a WM_VBXEVENT message with the
registered notification code of the default event.
For example if you were to register this event as follows:
UINT VBN_DEFAULTEVENT = AfxRegisterVBEvent("Default VBEvent");
Then the VBX emulation layer will send a WM_VBXEVENT message
with the VBN_DEFAULTEVENT notification code. You can still
unpack the event information to find what the "true" event was
that generated this message. The nEventIndex member of the
AFX_VBXEVENTPARAMS structure will have the id of the "true" event
that caused the notification to be sent. See MFC TechNotes 24
and 27 for more details on the WM_VBXEVENT message and the
AFX_VBXEVENTPARAMS structure.
REFERENCES
==========
MFC TechNote #24 describes private MFC messages including
the WM_VBXEVENT message.
MFC TechNote #27 describes MFC's emulation support for VBX
controls including how events are packed and sent as
parameters.
Additional reference words: 1.00 1.50 2.00 2.50 kbinf ctl vb
KBCategory: kbprg
KBSubcategory: MfcVBX
Keywords : kb16bitonly
Issue type :
Technology : kbAudDeveloper kbMFC