public static extern long WFSStartUp(int dwVersionsRequired, LPWFSVERSION lpWFSVersion);
public static extern long WFSAsyncOpen(string lpszLogicalName, IntPtr hApp, string lpszAppID, int dwTraceLevel, int dwTimeOut, ref ushort lphService, IntPtr hWnd, int dwSrvcVersionsRequired, LPWFSVERSION lpSrvcVersion, LPWFSVERSION lpSPIVersion, ref ulong lpRequestID);