LINE_MONITORDIGITS

The LINE_MONITORDIGITS message is sent when a digit is detected. The sending of this message is controlled with the lineMonitorDigits function.

LINE_MONITORDIGITS
dwDevice = (DWORD) hCall;
dwCallbackInstance = (DWORD) hCallback;
dwParam1 = (DWORD) Digit;
dwParam2 = (DWORD) DigitMode;
dwParam3 = (DWORD) 0;
 

Parameters

dwDevice

A handle to the call.

dwCallbackInstance

The callback instance supplied when opening the call's line.

dwParam1

The low-order byte contains the last digit received in ASCII.

dwParam2

The digit mode that was detected. This parameter must be one and only one of the following LINEDIGITMODE_ constants:

LINEDIGITMODE_PULSE

Detect digits as audible clicks that are the result of rotary pulse sequences. Valid digits for pulse are '0' through '9'.

LINEDIGITMODE_DTMF

Detect digits as DTMF tones. Valid digits for DTMF are '0' through '9', 'A', 'B', 'C', 'D', '*', and '#'.

LINEDIGITMODE_DTMFEND

Detect and provide application notification of DTMF down edges. Valid digits for DTMF are '0' through '9', 'A', 'B', 'C', 'D', '*', and '#'.

dwParam3

The "tick count" (number of milliseconds since Windows started) at which the specified digit was detected. For API versions earlier than 2.0, this parameter is unused.

Return Values

No return value.

Remarks

The LINE_MONITORDIGITS message is sent to the application that has enabled digit monitoring.

Because this timestamp may have been generated on a computer other than the one on which the application is executing, it is useful only for comparison to other similarly timestamped messages generated on the same line device (LINE_GATHERDIGITS, LINE_GENERATE, LINE_MONITORMEDIA, LINE_MONITORTONE), in order to determine their relative timing (separation between events). The tick count can "wrap around" after approximately 49.7 days; applications must take this into account when performing calculations.

If the service provider does not generate the timestamp (for example, if it was created using an earlier version of TAPI), then TAPI provides a timestamp at the point closest to the service provider generating the event so that the synthesized timestamp is as accurate as possible.

QuickInfo

  Version: Use TAPI version 1.4 and later.
  Header: Declared in tapi.h.

See Also

LINE_GATHERDIGITS, LINE_GENERATE, LINE_MONITORMEDIA, LINE_MONITORTONE, lineMonitorDigits