phoneSetHookSwitch function (tapi.h)

Article
02/22/2024

The phoneSetHookSwitch function sets the hook state of the specified open phone's hookswitch devices to the specified mode. Only the hookswitch state of the hookswitch devices listed is affected.

Syntax

LONG phoneSetHookSwitch(
  HPHONE hPhone,
  DWORD  dwHookSwitchDevs,
  DWORD  dwHookSwitchMode
);

Parameters

hPhone

Handle to the open phone device. The application must be the owner of the phone.

dwHookSwitchDevs

Device whose hookswitch mode is to be set. This parameter uses one and only one of the PHONEHOOKSWITCHDEV_ Constants.

PHONEHOOKSWITCHDEV_HANDSET

The phone's handset.

PHONEHOOKSWITCHDEV_SPEAKER

The phone's speakerphone or adjunct.

PHONEHOOKSWITCHDEV_HEADSET

The phone's headset.

dwHookSwitchMode

Hookswitch mode to set. This parameter uses one and only one of the PHONEHOOKSWITCHMODE_ Constants.

PHONEHOOKSWITCHMODE_ONHOOK

The device's microphone and speaker are both onhook.

PHONEHOOKSWITCHMODE_MIC

The device's microphone is active, the speaker is mute.

PHONEHOOKSWITCHMODE_SPEAKER

The device's speaker is active, the microphone is mute.

PHONEHOOKSWITCHMODE_MICSPEAKER

The device's microphone and speaker are both active.

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_OPERATIONUNAVAIL, PHONEERR_NOTOWNER, PHONEERR_NOMEM, PHONEERR_INVALHOOKSWITCHDEV, PHONEERR_RESOURCEUNAVAIL, PHONEERR_INVALHOOKSWITCHMODE, PHONEERR_OPERATIONFAILED, PHONEERR_INVALPHONESTATE, PHONEERR_UNINITIALIZED.

Remarks

The hookswitch mode is the same for all specified devices. If different settings are desired, this function can be invoked multiple times with a different set of parameters. A PHONE_STATE message is sent to the application after the hookswitch state has changed.

Requirements

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