PHONE_BUTTON message

The TAPI PHONE_BUTTON message is sent to notify the application that button press monitoring is enabled if it has detected a button press on the local phone.

Parameters

hPhone

A handle to the phone device.

dwCallbackInstance

The application's callback instance provided when opening the phone device.

dwParam1

The button/lamp identifier of the button that was pressed. Note that button identifiers zero through 11 are always the KEYPAD buttons, with '0' being button identifier zero, '1' being button identifier 1 (and so on through button identifier 9), and with '*' being button identifier 10, and '#' being button identifier 11. Additional information about a button identifier is available with phoneGetDevCaps and phoneGetButtonInfo.

dwParam2

The button mode of the button. This parameter uses one of the PHONEBUTTONMODE_ constants.

dwParam3

Specifies whether this is a button-down event or a button-up event. This parameter uses one of the PHONEBUTTONSTATE_ constants.

Return value

No return value.

Remarks

A PHONE_BUTTON message is sent whenever a button changes state. An application is guaranteed that for each button down event, it is eventually sent a corresponding button up event. A service provider that is incapable of detecting the actual button up is required to generate the button up message shortly after the button down message for each button press.

Requirements

Requirement	Value
TAPI version	Requires TAPI 2.0 or later
Header	Tapi.h

See also

phoneGetButtonInfo

phoneGetDevCaps