lineGetID

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

LONG WINAPI 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. An address identifier is permanently associated with an address; the identifier remains constant across operating system upgrades.

hCall

A handle to a call.

dwSelect

Specifies whether the requested device identifier is associated with the line, address or a single call. This parameter uses one and only one of the LINECALLSELECT_ Constants.

lpDeviceID

A pointer to a memory location of type VARSTRING, where the device identifier is returned. Upon successful completion of the request, this location is filled with the device identifier. 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 member of this structure to indicate the amount of memory available to TAPI for returning information.

lpszDeviceClass

A pointer to a null-terminated string that specifies the device class of the device whose identifier 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 succeeds or a negative error number if an error occurs. 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 identifier when given a line handle. This is useful after lineOpen has been opened using LINEMAPPER as a device identifier in order to determine the real line-device identifier of the opened line. This function can also be used to obtain the device identifier 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 identifier 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 TAPI Device Classes 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".

Requirements

  Windows NT/2000: Requires Windows NT 4.0 SP3 or later.
  Windows 95/98: Requires Windows 95 or later.
  Version: Requires TAPI 1.3 or later.
  Header: Declared in Tapi.h.
  Library: Use Tapi32.lib.
  Unicode: Implemented as Unicode and ANSI versions on all platforms.

See Also

TAPI 2.2 Reference Overview, Basic Telephony Services Reference, lineOpen, VARSTRING