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LINE_GENERATE (TAPI) (Compact 2013)

  • Статья

3/26/2014

This message is sent to notify the application that the current digit or tone generation has terminated. Only one such generation request can be in progress on a given call at any time. This message is also sent when digit or tone generation is canceled.

Syntax

LINE_GENERATE
    hDevice = (DWORD) hCall;
    dwCallbackInstance = (DWORD) hCallback;
    dwParam1 = (DWORD) GenerateTermination;
    dwParam2 = (DWORD) 0;
    dwParam3 = (DWORD) 0;

Parameters

  • hDevice
    Handle to the call.
  • dwCallbackInstance
    Callback instance supplied when opening the line.
  • dwParam1
    Reason why digit or tone generation was terminated. This parameter must be one and only one of the LINEGENERATETERM constants.
  • dwParam2
    Not used by this message. Value is NULL.
  • dwParam3
    Tick count (the number of milliseconds since Windows started) at which the digit or tone generation completed. For API versions earlier than 2.0, this parameter is not used.

Return Value

None.

Remarks

The LINE_GENERATE message is only sent to the application that requested the digit or tone generation.

Because the timestamp specified by dwParam3 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_MONITORDIGITS (TAPI), LINE_MONITORMEDIA (TAPI)), 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, 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.

Requirements

Header

tapi.h

See Also

Reference

TAPI Messages
LINE_MONITORDIGITS (TAPI)
LINE_MONITORMEDIA (TAPI)