C / C++ / MFC

midiInOpen(&hMidiIn, CurInDevice, (DWORD)MyCallback, NULL, CALLBACK_FUNCTION);

void CALLBACK MyCallback(HMIDIIN hMidiIn, UINT wMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2)
{

int iResult;

switch(wMsg)
{

case MIM_DATA:
{
iResult = Zones->PostMessage(WM_MIDIEVENT);  //Zones is the Main-Window of my Dialog-based App
ASSERT(iResult);
break;
}

case MIM_MOREDATA: break;
case MIM_OPEN: break;
case MIM_CLOSE: break;

default:
ASSERT(0);

}

#define WM_MIDIEVENT   WM_USER+100

ON_MESSAGE(WM_MIDIEVENT, OnMidiEvent)

void CZones::OnMidiEvent()
{
}

afx_msg void OnMyMessage(void);

afx_msg LRESULT OnMyMessage(WPARAM, LPARAM);

void MyDialog::OnMyMessage(void);

LRESULT MyDialog::OnMyMessage(WPARAM, LPARAM);

// like ON_MESSAGE but no return value
#define ON_MESSAGE_VOID(message, memberFxn) \
	{ message, 0, 0, 0, AfxSig_vv, \
		(AFX_PMSG)(AFX_PMSGW)(void (AFX_MSG_CALL CWnd::*)(void))&memberFxn },

HIMAGELIST CImageList::Detach()
{
HIMAGELIST hImageList = m_hImageList;
 
    if (hImageList != NULL)
        {
        CHandleMap* pMap = afxMapHIMAGELIST();
        if (pMap != NULL)
            pMap->RemoveHandle(m_hImageList);
        }
 
    m_hImageList = NULL;
    return hImageList;
}

BOOL CButtonDlg::PreTranslateMessage(MSG* pMsg) 
{
	// TODO: Add your specialized code here and/or call the base class
	if ((pMsg->message == WM_LBUTTONDOWN && pMsg->hwnd == GetDlgItem(IDC_BUTTON1)->GetSafeHwnd())
		|| pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_RETURN &&
		pMsg->hwnd == GetDlgItem(IDC_BUTTON1)->GetSafeHwnd())
//		MessageBox ("Click button", "Test");
		TRACE ("Click or push the button");

	return CDialog::PreTranslateMessage(pMsg);
}
</br>

CTestDlg::OnCommand(WPARAM wParam, LPARAM lParam)
{
    if (HIWORD(wParam) == BN_CLICKED) // a button was clicked
    {
        if (LOWORD(wParam) == myButtonID) // my button was clicked
        {
            MessageBox("Y");
            return TRUE;
        }
    }
    return CDialog::OnCommand(wParam, lParam);
}