public static extern bool FindNextPrinterChangeNotification([In()] IntPtr hChangeObject,
                                                             [Out()] out Int32 pdwChange,
                                                             [In(), MarshalAs(UnmanagedType.LPStruct)] PRINTER_NOTIFY_OPTIONS pPrinterNotifyOptions,
                                                             [Out()] out IntPtr lppPrinterNotifyInfo);
 public static extern IntPtr FindFirstPrinterChangeNotification([In()] IntPtr hPrinter, [In()] Int32 fwFlags,
                                                                [In()] Int32 fwOptions,
                                                                [In(), MarshalAs(UnmanagedType.LPStruct)] PRINTER_NOTIFY_OPTIONS pPrinterNotifyOptions);