LINE_CALLINFO (TAPI)

  • 项目

This message is sent when the call information about the specified call has changed. The application can invoke lineGetCallInfo to determine the current call information.

LINE_CALLINFO 
  dwDevice = (DWORD) hCall; 
  dwCallbackInstance = (DWORD) hCallback;
  dwParam1 = (DWORD) CallInfoState; 
  dwParam2 = (DWORD) 0;
  dwParam3 = (DWORD) 0;

Parameters

  • dwDevice
    Handle to the call.
  • dwCallbackInstance
    Callback instance supplied when opening the call's line.
  • dwParam1
    Value that specifies the call information item that has changed. It can be a combination of values using the LINECALLINFOSTATE.
  • dwParam2
    Not used by this message. Value is NULL.
  • dwParam3
    Not used by this message. Value is NULL.

Return Values

None.

Remarks

A LINE_CALLINFO message with a NumOwnersIncr, NumOwnersDecr, and/or NumMonitorsChanged indication is sent to applications that already have a handle for the call. This can be the result of another application changing ownership or monitorship to a call with lineOpen, lineClose, and lineShutdown.

These LINE_CALLINFO messages are not sent when a notification of a new call is provided in a LINE_CALLSTATE (TAPI) message, because the call information already reflects the correct number of owners and monitors at the time the LINE_CALLSTATE messages are sent. LINE_CALLINFO messages are also suppressed in the case where a call is offered by TAPI to monitors through the LINECALLSTATE_UNKNOWN mechanism.

Note   The application that causes a change in the number of owners or monitors, for example, by invoking the lineDeallocateCall or lineSetCallPrivilege functions, does not itself receive a message indicating that the change has been done.

No LINE_CALLINFO messages are sent for a call after the call has entered the idle state. Specifically, changes in the number of owners and monitors are not reported as applications de-allocate their handles for the idle call.

Requirements

OS Versions: Windows CE 3.0 and later.
Header: Tapi.h.

See Also

lineClose | lineDeallocateCall | lineGetCallInfo | lineOpen | lineSetCallPrivilege | lineShutdown | LINE_CALLSTATE (TAPI)

 Last updated on Saturday, April 10, 2004

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