phoneDevSpecific function (tapi.h)

Article
10/05/2021

The phoneDevSpecific function is used as a general extension mechanism to enable a Telephony API implementation to provide features not described in the other TAPI functions. The meanings of these extensions are device specific.

Syntax

LONG phoneDevSpecific(
  HPHONE hPhone,
  LPVOID lpParams,
  DWORD  dwSize
);

Parameters

hPhone

Handle to a phone device.

lpParams

Pointer to a memory area used to hold a parameter block. Its interpretation is device specific. The contents of the parameter block are passed unchanged to or from the service provider by TAPI.

dwSize

Size of the parameter block area, in bytes.

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 PHONE_REPLY message is zero if the function succeeds or it is a negative error number if an error occurs. Possible return values are:

PHONEERR_INVALPHONEHANDLE, PHONEERR_NOMEM, PHONEERR_INVALPOINTER, PHONEERR_RESOURCEUNAVAIL, PHONEERR_OPERATIONUNAVAIL, PHONEERR_UNINITIALIZED, PHONEERR_OPERATIONFAILED.

Additional return values are device specific.

Remarks

This operation provides a generic parameter profile. The interpretation of the parameter block is device specific. Indications and replies that are device specific should use the PHONE_DEVSPECIFIC message.

A service provider can provide access to device-specific functions by defining parameters for use with this operation. Applications that want to make use of these device-specific extensions should consult the device-specific (vendor-specific) documentation that describes which extensions are defined. Typically, an application that relies on these device-specific extensions is not portable to work with other service-provider environments.

Requirements

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