phoneGetHookSwitch function (tapi.h)

Article
10/05/2021

The phoneGetHookSwitch function returns the current hookswitch mode of the specified open phone device.

Syntax

LONG phoneGetHookSwitch(
  HPHONE  hPhone,
  LPDWORD lpdwHookSwitchDevs
);

Parameters

hPhone

Handle to the open phone device.

lpdwHookSwitchDevs

Pointer to a DWORD to be filled with the mode of the phone's hookswitch devices. If a bit position is FALSE, the corresponding hookswitch device is onhook; if TRUE, the microphone and/or speaker part of the corresponding hookswitch device is offhook. To find out whether the microphone and/or speaker are enabled, the application can use phoneGetStatus. This parameter uses one or more of the PHONEHOOKSWITCHDEV_ Constants.

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_INVALPOINTER, PHONEERR_RESOURCEUNAVAIL, PHONEERR_INVALPHONESTATE, PHONEERR_OPERATIONFAILED, PHONEERR_OPERATIONUNAVAIL, PHONEERR_UNINITIALIZED.

Remarks

After the hookswitch state of a device changes, and if hookswitch monitoring is enabled, the application is sent a PHONE_STATE message.

Requirements

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