NMHDR nm;
nm.code = 123456;  // 这里是消息的区别代码
nm.hwndFrom = m_hWnd;//这是控件的HWND句柄
nm.idFrom = GetDlgCtrlID();//这是得到的对话框的ID

CWnd*  pWnd;
    pWnd = GetParent();  //得到父窗体 窗口
    if (pWnd != NULL)
    {
        pWnd->SendMessage(WM_NOTIFY, nm.idFrom, (LPARAM)&nm);  //向父窗体发送消息
    }

BOOL CMyControlDlg::OnNotify(WPARAM wParam, LPARAM lParam, LRESULT* pResult)
{

    if ((UINT)wParam == IDC_CUSTOM2)
    {
        AfxMessageBox(_T("成功"));
    }
    return CDialogEx::OnNotify(wParam, lParam, pResult);
}