linePrepareAddToConferenceA function (tapi.h)

The linePrepareAddToConference function prepares an existing conference call for the addition of another party.

Syntax

LONG linePrepareAddToConferenceA(
  HCALL                  hConfCall,
  LPHCALL                lphConsultCall,
  LPLINECALLPARAMS const lpCallParams
);

Parameters

hConfCall

Handle to a conference call. The application must be an owner of this call. The call state of hConfCall must be connected.

lphConsultCall

Pointer to an HCALL handle. This location is then loaded with a handle identifying the consultation call to be added. Initially, the application is the sole owner of this call.

lpCallParams

Pointer to a LINECALLPARAMS structure containing call parameters to use when establishing the consultation call. This parameter can be set to NULL if no special call setup parameters are desired.

Return value

Returns a positive request identifier if the function is completed asynchronously, or a negative error number if an error occurs. The dwParam2 parameter of the corresponding LINE_REPLY message is zero if the function succeeds or it is a negative error number if an error occurs. Possible return values are:

LINEERR_BEARERMODEUNAVAIL, LINEERR_INVALPOINTER, LINEERR_CALLUNAVAIL, LINEERR_INVALRATE, LINEERR_CONFERENCEFULL, LINEERR_NOMEM, LINEERR_INUSE, LINEERR_NOTOWNER, LINEERR_INVALADDRESSMODE, LINEERR_OPERATIONUNAVAIL, LINEERR_INVALBEARERMODE, LINEERR_OPERATIONFAILED, LINEERR_INVALCALLPARAMS, LINEERR_RATEUNAVAIL, LINEERR_INVALCALLSTATE, LINEERR_RESOURCEUNAVAIL, LINEERR_INVALCONFCALLHANDLE, LINEERR_STRUCTURETOOSMALL, LINEERR_INVALLINESTATE, LINEERR_USERUSERINFOTOOBIG, LINEERR_INVALMEDIAMODE, LINEERR_UNINITIALIZED.

Remarks

If LINEERR_INVALLINESTATE is returned, the line is currently not in a state in which this operation can be performed. A list of currently valid operations can be found in the dwLineFeatures member (of the type LINEFEATURE) in the LINEDEVSTATUS structure. (Calling lineGetLineDevStatus updates the information in LINEDEVSTATUS.)

A conference call handle can be obtained with lineSetupConference or with lineCompleteTransfer that is resolved as a three-way conference call. The linePrepareAddToConference function typically places the existing conference call in the onHoldPendingConference state and creates a consultation call that can be added later to the existing conference call with lineAddToConference.

The consultation call can be canceled using lineDrop. It may also be possible for an application to swap between the consultation call and the held conference call with lineSwapHold.

Note

The tapi.h header defines linePrepareAddToConference as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement Value
Target Platform Windows
Header tapi.h
Library Tapi32.lib
DLL Tapi32.dll

See also

Conference overview

LINECALLPARAMS

LINEDEVSTATUS

LINE_REPLY

Supplementary Line Service Functions

lineAddToConference

lineCompleteTransfer

lineDrop

lineGetLineDevStatus

lineSetupConference

lineSwapHold