phoneGetVolume function (tapi.h)

The phoneGetVolume function returns the volume setting of the specified phone's hookswitch device.

Syntax

LONG phoneGetVolume(
  HPHONE  hPhone,
  DWORD   dwHookSwitchDev,
  LPDWORD lpdwVolume
);

Parameters

hPhone

Handle to the open phone device.

dwHookSwitchDev

A single hookswitch device whose volume level is queried. This parameter uses one of the PHONEHOOKSWITCHDEV_ Constants.

lpdwVolume

Pointer to a DWORD. The function returns the current volume setting of the hookswitch device in this location. This is a number in the range 0x00000000 (silence) to 0x0000FFFF (maximum volume). The actual granularity and quantization of volume settings in this range are service provider-specific.

Return value

Returns zero if the request succeeds or a negative error number if an error occurs. Possible return values are:

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

Requirements

See also

Supplementary Phone Service Functions

TAPI 2.2 Reference Overview