Does exist a ON_COMMAND_EX version accepting a function returning void?

Question

I searched but I didn't found. I want a Message map macro that links the menu item command action to a function accepting the numeric ID and providing no return at all (being void).

ON_COMMAND returns void, but it is too limited, because it does not provide the menu item ID, which I need in this case.

ON_COMMAND_EX returns a BOOL, so it forces me to do a lot of returns, which would be unneeded if the return type was void.

So, as I described in first paragraph, is there such a macro?

score 0 · Answer 1 · edited Apr 18 '16 at 17:56

0

You can use:

ON_COMMAND_RANGE(ID_COMMAND, ID_COMMAND, Handler)

edited Apr 18 '16 at 17:56

keithbhunter

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answered Jan 04 '16 at 21:39

Lyudmil Zahariev

1

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Can you explain more your answer please ? – Zulu Jan 04 '16 at 21:43

score 0 · Accepted Answer · edited May 23 '17 at 12:16

I didn't found such a macro but I came with a solution: Define my own macro based on the definition of ON_COMMAND_EX, replacing BOOL by void.

The ON_COMMAND_EX macro is:

#define ON_COMMAND_EX(id, memberFxn) \
    { WM_COMMAND, CN_COMMAND, (WORD)id, (WORD)id, AfxSigCmd_EX, \
        (AFX_PMSG) \
        (static_cast< BOOL (AFX_MSG_CALL CCmdTarget::*)(UINT) > \
    (memberFxn)) },

I've just copied and adapted it to my own purposes:

#define ON_COMMAND_EX_VOID(id, memberFxn) \
    { WM_COMMAND, CN_COMMAND, (WORD)id, (WORD)id, AfxSigCmd_EX, \
        (AFX_PMSG) \
        (static_cast< void (AFX_MSG_CALL CCmdTarget::*)(UINT) > \
    (memberFxn)) },

Notice the only two changes are the name of tha macro and change from BOOL to void

To use it: On the message map, add something like

    ON_COMMAND_EX_VOID(ID_FILE_PREFERENCES, OnFilePreferencesVoid)

Then declare the handler function on the header file: afx_msg void OnFilePreferencesVoid(UINT nID);

And finally do the implementation on the source code file:

void CMainFrame::OnFilePreferencesVoid(UINT nID)
{
    CString s;
    s.Format(_T("%d"), nID);
    AfxMessageBox(s);
}

Obviously, the code posted here is a theoretical example, as there are more useful things to do than display an already annoying popup message with an irritant resource ID.

The inspiration for the solution came from ON_MESSAGE_VOID posted on https://stackoverflow.com/a/10619963/383779

Does exist a ON_COMMAND_EX version accepting a function returning void?

2 Answers2