4.21 WFSAsyncRegister

HRESULT WFSAsyncRegister( hService, dwEventClass, hWndReg, hWnd, lpRequestID )

Enables event monitoring for the specified service by the specified window; all messages of the specified class(es) are sent to the window specified in the hWndReg parameter. The asynchronous version of WFSRegister.

Parameters HSERVICE hService

Handle to the service provider as returned by WFSOpen or WFSAsyncOpen. If this value is NULL, and dwEventClass is SYSTEM_EVENTS, the XFS manager registers the application for those system events generated by the Manager itself.

DWORD dwEventClass

See WFSRegister.

HWND hWndReg

The window handle which is to be registered to receive the specified messages.

HWND hWnd

The window handle which is to receive the completion message for this request.

LPREQUESTID lpRequestID

Pointer to the request identifier for this request (returned parameter).

Mode Asynchronous

Comments See WFSRegister.

The application must call WFSFreeResult to deallocate the WFSRESULT data structure pointed to by the completion message. Note that a WFSRESULT structure may be returned even if the function completes with an error; see Section 3.13.

Messages WFS_REGISTER_COMPLETE

Error Codes If the function return is not WFS_SUCCESS, it is one of the following error conditions, indicating that the asynchronous operation was not initiated:

WFS_ERR_CONNECTION_LOST

The connection to the service is lost.

WFS_ERR_INTERNAL_ERROR

An internal inconsistency or other unexpected error occurred in the WOSA/XFS subsystem.

WFS_ERR_INVALID_EVENT_CLASS

The dwEventClass parameter specifies one or more event classes not supported by the service.

WFS_ERR_INVALID_HSERVICE

The hService parameter is not a valid service handle.

WFS_ERR_INVALID_HWND

The hWnd parameter is not a valid window handle.

WFS_ERR_INVALID_HWNDREG

The hWndReg parameter is not a valid window handle.

WFS_ERR_NOT_STARTED

The application has not previously performed a successful WFSStartUp.

WFS_ERR_OP_IN_PROGRESS

A blocking operation is in progress on the thread; only WFSCancelBlockingCall and WFSIsBlocking are permitted at this time.

The following error conditions can be returned via the asynchronous command completion message, as the hResult from the WFSRESULT structure.

WFS_ERR_CANCELED

The request was canceled by WFSCancelAsyncRequest.

WFS_ERR_INTERNAL_ERROR

An internal inconsistency or other unexpected error occurred in the WOSA/XFS subsystem.

See also WFSRegister, WFSDeregister, WFSAsyncDeregister