TSPI_lineMonitorDigits
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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 modes is detected, a LINE_MONITORDIGITS message is sent to the application by TAPI, indicating which digit is detected.
Syntax
LONG TSPIAPI TSPI_lineMonitorDigits(
HDRVCALL hdCall,
DWORD dwDigitModes
);
Parameters
- hdCall
Handle to the call on which digits are to be detected. The call state of hdCall can be any state except idle or disconnected.
- dwDigitModes
Digit modes that are to be monitored. A dwDigitModes parameter with a value of zero cancels digit monitoring. The dwDigitModes parameter can have one of the LINEDIGITMODE constants.
Return Value
Returns zero if the function succeeds, or an error number if an error occurs.
Value | Description |
---|---|
LINEERR_INVALCALLHANDLE |
The handle to the call is invalid. |
LINEERR_OPERATIONUNAVAIL |
The operation is unavailable. |
LINEERR_INVALCALLSTATE |
The call state is invalid. |
LINEERR_OPERATIONFAILED |
The operation failed. |
LINEERR_INVALDIGITMODE |
The digit mode is invalid. |
LINEERR_RESOURCEUNAVAIL |
The resource is unavailable. |
LINEERR_NOMEM |
Not enough memory is available. |
Remarks
This function returns zero (success) when digit monitoring is correctly initiated, not when digit monitoring is terminated. Digit monitoring remains in effect until it is explicitly disabled by a call to TSPI_lineMonitorDigits with dwDigitModes set to zero, or until the call transitions to idle. The function must return zero when digit monitoring is canceled (that is, when the dwDigitModes parameter is zero). The service provider must terminate digit monitoring when the call goes idle. TAPI does not spontaneously call TSPI_lineMonitorDigits to terminate monitoring.
Although this function can be invoked in any call state, digits typically are detected only while the call is in the connected state.
Each time a digit is detected, the service provider sends a LINE_MONITORDIGITS message to TAPI, passing the detected digit as a parameter. If both LINEDIGITMODE_DTMF and LINEDIGITMODE_DTMFEND are set in dwDigitModes, the two LINE_MONITORDIGITS messages are sent for each digit.
TAPI can use TSPI_lineMonitorDigits to enable or disable unbuffered digit detection.
Requirements
Header | tapicomn.h |
Library | coredll.lib |
Windows Embedded CE | Windows CE 3.0 and later |
Windows Mobile | Windows Mobile Version 5.0 and later |