Export (0) Print
Expand All
This topic has not yet been rated - Rate this topic

Event Maps

Whenever a control wishes to notify its container that some action (determined by the control developer) has happened (such as a keystroke, mouse click, or a change to the control's state) it calls an event-firing function. This function notifies the control container that some important action has occurred by firing the related event.

The Microsoft Foundation Class Library offers a programming model optimized for firing events. In this model, "event maps" are used to designate which functions fire which events for a particular control. Event maps contain one macro for each event. For example, an event map that fires a stock Click event might look like this:

BEGIN_EVENT_MAP(CMyAxCtrl, COleControl)
   EVENT_STOCK_CLICK()
END_EVENT_MAP()

The EVENT_STOCK_CLICK macro indicates that the control will fire a stock Click event every time it detects a mouse click. For a more detailed listing of other stock events, see the article ActiveX Controls: Events. Macros are also available to indicate custom events.

Although event-map macros are important, you generally do not insert them directly. This is because the Properties window automatically creates event-map entries in your source files when you use it to associate event-firing functions with events. Any time you want to edit or add an event-map entry, you can use the Properties window.

To support event maps, MFC provides the following macros:

Event Map Declaration and Demarcation

DECLARE_EVENT_MAP

Declares that an event map will be used in a class to map events to event-firing functions (must be used in the class declaration).

BEGIN_EVENT_MAP

Begins the definition of an event map (must be used in the class implementation).

END_EVENT_MAP

Ends the definition of an event map (must be used in the class implementation).

Event Mapping Macros

EVENT_CUSTOM

Indicates which event-firing function will fire the specified event.

EVENT_CUSTOM_ID

Indicates which event-firing function will fire the specified event, with a designated dispatch ID.

Message Mapping Macros

ON_OLEVERB

Indicates a custom verb handled by the OLE control.

ON_STDOLEVERB

Overrides a standard verb mapping of the OLE control.

Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2014 Microsoft. All rights reserved.