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Purpose of afx_msg keyword?

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Topic: Purpose of afx_msg keyword?

Posted By: znakeeye
Subject: Purpose of afx_msg keyword?
Date Posted: 17 August 2009 at 10:48am

What's the purpose of afx_msg?

E.g.

afx_msg void OnPaint();

Is it merely there to make it easier for VC++ to add message-handlers? Is it even needed in VC++ 2008?

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Replies:

Posted By: ABuenger
Date Posted: 17 August 2009 at 11:19am

ClassWizard requires that you use the afx_msg keyword in your message map handler declarations.

http://msdn.microsoft.com/en-us/library/0812b0wa%28VS.80%29.aspx - http://msdn.microsoft.com/en-us/library/0812b0wa(VS.80).aspx

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Posted By: znakeeye
Date Posted: 18 August 2009 at 6:59am

Thanks! I've been looking for that article! :D

Finally I got the answer to why command-handlers are not simply virtual member functions:

"Due to the large number of messages involved, providing a separate virtual function for each Windows message results in a prohibitively large vtable."

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