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 prior to 0x00020000, 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 will provide a timestamp
at the point closest to the service provider generating the event so that the
synthesized timestamp is as accurate as possible.
See Also