Question

Using CoreFoundation, I can display an alert dialog with the following:

CFUserNotificationDisplayAlert(0.0, 
                               kCFUserNotificationPlainAlertLevel, 
                               NULL, NULL, NULL, 
                               CFSTR("Alert title"), 
                               CFSTR("Yes?), 
                               CFSTR("Affirmative"), 
                               CFSTR("Nah"), 
                               NULL, NULL);

How do I replicate this using the Windows C API? The closest I’ve gotten is:

MessageBox(NULL, "Yes?", "Alert title", MB_OKCANCEL);

but that hard-codes “OK” and “Cancel” as the button titles, which is not what I want. Is there any way around this, or an alternative function to use?

Answer 1

You can use SetWindowText to change the legend on the buttons. Because the MessageBox() blocks the flow of execution you need some mechanism to get round this – the code below uses a timer.

I think the FindWindow code may be dependent on there being no parent for MessageBox() but I’m not sure.

int CustomMessageBox(HWND hwnd, const char * szText, const char * szCaption, int nButtons)
{
    SetTimer( NULL, 123, 0, TimerProc );
    return MessageBox( hwnd, szText, szCaption, nButtons );
}

VOID CALLBACK TimerProc(      
    HWND hwnd,
    UINT uMsg,
    UINT_PTR idEvent,
    DWORD dwTime
)
{
    KillTimer( hwnd, idEvent );
    HWND hwndAlert;
    hwndAlert = FindWindow( NULL, "Alert title" ); 
    HWND hwndButton;
    hwndButton = GetWindow( hwndAlert, GW_CHILD );
    do
    {
        char szBuffer[512];
        GetWindowText( hwndButton, szBuffer, sizeof szBuffer );
        if ( strcmp( szBuffer, "OK" ) == 0 )
        {
            SetWindowText( hwndButton, "Affirmative" );
        }
        else if ( strcmp( szBuffer, "Cancel" ) == 0 )
        {
            SetWindowText( hwndButton, "Hah" );
        }
    } while ( (hwndButton = GetWindow( hwndButton, GW_HWNDNEXT )) != NULL );
}