lineGetID

The lineGetID function returns a device ID for the specified device class associated with the selected line, address, or call.

LONG lineGetID(

HLINE hLine,
DWORD dwAddressID,
HCALL hCall,
DWORD dwSelect,
LPVARSTRING lpDeviceID,
LPCSTR lpszDeviceClass
);

Parameters
hLine

A handle to an open line device.

dwAddressID

An address on the given open line device.

hCall

A handle to a call.

dwSelect

Specifies whether the requested device ID is associated with the line, address or a single call. The dwSelect parameter can only have a single flag set. This parameter uses the following LINECALLSELECT_ constants:

LINECALLSELECT_LINE

Selects the specified line device. The hLine parameter must be a valid line handle; hCall and dwAddressID are ignored.

LINECALLSELECT_ADDRESS

Selects the specified address on the line. Both hLine and dwAddressID must be valid; hCall is ignored.

LINECALLSELECT_CALL

Selects the specified call. hCall must be valid; hLine and dwAddressID are both ignored.

lpDeviceID

A pointer to a memory location of type VARSTRING, where the device ID is returned. Upon successful completion of the request, this location is filled with the device ID. The format of the returned information depends on the method used by the device class API for naming devices. Prior to calling lineGetID, the application should set the dwTotalSize field of this structure to indicate the amount of memory available to TAPI for returning information.

lpszDeviceClass

A pointer to a NULL-terminated ASCII string that specifies the device class of the device whose ID is requested. Valid device class strings are those used in the SYSTEM.INI section to identify device classes.

Return Values
Returns zero if the request is successful or a negative error number if an error has occurred. Possible return values are:

LINEERR_INVALLINEHANDLE, LINEERR_NOMEM, LINEERR_INVALADDRESSID, LINEERR_OPERATIONUNAVAIL, LINEERR_INVALCALLHANDLE, LINEERR_OPERATIONFAILED, LINEERR_INVALCALLSELECT, LINEERR_RESOURCEUNAVAIL, LINEERR_INVALPOINTER, LINEERR_STRUCTURETOOSMALL, LINEERR_NODEVICE, LINEERR_UNINITIALIZED.

Remarks
The lineGetID function can be used to retrieve a line-device ID when given a line handle. This is useful after a line device has been opened using LINEMAPPER as a device ID in order to determine the real line-device ID of the opened line. This function can also be used to obtain the device ID of a phone device or media device (for device classes such as COM, wave, MIDI, phone, line, or NDIS) associated with a call, address or line. This ID can then be used with the appropriate API (such as phone, midi, wave) to select the corresponding media device associated with the specified call.

See Device Classes in TAPI for device class names.

A vendor that defines a device-specific media mode also needs to define the corresponding device-specific (proprietary) API to manage devices of the media mode. To avoid collisions on device class names assigned independently by different vendors, a vendor should select a name that uniquely identifies both the vendor and, following it, the media type. For example: "intel/video".