C / C++ / MFC

afx_msg BOOL OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message);

BOOL CDisplayPrintTemplate::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message) 
{
	AfxMessageBox("hrm");
	::SetCursor(AfxGetApp()->LoadCursor (IDC_HAND_OPEN));
	return 0;
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    static BOOL bMouseInside;

    switch (message) 
    {

        case WM_MOUSEMOVE:
            {
                TRACKMOUSEEVENT tme;
                tme.cbSize = sizeof(tme);
                tme.hwndTrack = hWnd;
                tme.dwFlags = TME_LEAVE;

                _TrackMouseEvent(&tme);

                if(!bMouseInside)
                {
                    bMouseInside = TRUE;
                    InvalidateRect(hWnd, NULL, FALSE);
                    UpdateWindow(hWnd);
                }
            }
            break;

        case WM_MOUSELEAVE:
            bMouseInside = FALSE;
            InvalidateRect(hWnd, NULL, FALSE);
            UpdateWindow(hWnd);
            break;

BOOL CMouseEvent::OnMouseMove....
{
    if( m_uTimer != 0 )
        return TRUE;

    m_uTimer = ::SetTimer( pWnd->m_hWnd, IDS_TIMER_MOUSE_EVENT, 10, NULL ); 
    if( m_uTimer )
    {
        m_hWnd = pWnd->m_hWnd;
        ::SendMessage( pWnd->m_hWnd, UWM_MOUSE_ENTER, 0, 0 );
    }

    return m_uTimer != 0 ? TRUE : FALSE ;
}


BOOL CMouseEvent::OnTimer(CWnd *pWnd )
{
    CPoint pt;
    ::GetCursorPos( &pt );

    if( pWnd != CWnd::WindowFromPoint( pt ) )
    {
        ::KillTimer( pWnd->m_hWnd, m_uTimer );
        m_uTimer = 0;
        m_hWnd = NULL;
        //mouse came out
    }

    return TRUE;
}