public void Show() { editToolTip ebt = new editToolTip(); ebt.cbStruct = Marshal.SizeOf(ebt); ebt.pszText = m_text; ebt.pszTitle = m_title; ebt.ttiIcon = (int)m_titleIcon; IntPtr ptrStruct = Marshal.AllocHGlobal(Marshal.SizeOf(ebt)); Marshal.StructureToPtr(ebt, ptrStruct, true); System.Diagnostics.Debug.Assert(m_parent != null, "Parent control is null", "Set parent before calling Show"); int ret = SendMessage(m_parent.Handle, EM_SHOWBALLOONTIP, 0, ptrStruct); Marshal.FreeHGlobal(ptrStruct); }