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4/8/2010

This function enables and disables the unbuffered detection of digits received on the call. Each time a digit of the specified digit mode is detected, a message is sent to the application indicating which digit has been detected.

Syntax 

LONG WINAPI lineMonitorDigits(
  HCALL 
hCall,
  DWORD 
dwDigitModes 
);

Parameters

hCall

Handle to the call on which digits are to be detected. The call state of hCallcan be any state except idle or disconnected.

dwDigitModes

Digit mode or modes that are to be monitored. If dwDigitModesis zero, digit monitoring is canceled. This parameter uses one or more of the LINEDIGITMODEconstants.

Return Value

Returns zero if the request succeeds or a negative error number if an error occurs. The following table shows the return values for this function.

Value Description

LINEERR_INVALCALLHANDLE

The handle to the call is invalid.

LINEERR_OPERATIONUNAVAIL

The operation is unavailable.

LINEERR_INVALCALLSTATE

The call state of hCallis either idle or disconnected.

LINEERR_OPERATIONFAILED

The operation failed.

LINEERR_INVALDIGITMODE

The digit mode is invalid.

LINEERR_RESOURCEUNAVAIL

The resources are unavailable.

LINEERR_NOMEM

Not enough memory is available.

LINEERR_UNINITIALIZED

A parameter is uninitialized.

Remarks

This function is considered successful if digit monitoring has been correctly initiated, not when digit monitoring has terminated. Digit monitoring remains in effect until it is explicitly disabled by calling lineMonitorDigitswith dwDigitModesset to zero, until the call transitions to idle, or when the application deallocates its call handle for the call. Although this function can be invoked in any call state, digits are usually detected only while the call is in the connected state.

Each time a digit is detected, a LINE_MONITORDIGITSmessage is sent to the application passing the detected digit as a parameter.

An application can use lineMonitorDigitsto enable or disable unbuffered digit detection. Monitoring of digits on a conference call applies only to the hConfCall, not to the individual participating calls.

Note:
This function is for TAPI version 2.0 and later.

Requirements

Header tapi.h
Library coredll.lib
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also