LINEEVENT

This type is a callback function implemented by TAPI and supplied to the service provider as a parameter to TSPI_lineOpen. The service provider calls this function to report events that occur on the line or on calls on the line.

LINEEVENT Line_Event; 
void(
  CALLBACK * Line_Event)(  
  HTAPILINE htLine,        
  HTAPICALL htCall,        
  DWORD dwMsg,             
  DWORD dwParam1,          
  DWORD dwParam2,          
  DWORD dwParam3           
);

Parameters

htLine

The TAPI handle for the line on which the event occurred.

htCall

The TAPI handle for the call on which the event occurred if this is a call-related event. For line-related events where there is no call, this parameter is set to NULL.

dwMsg

Specifies the kind of event that is being reported. Interpretation of the other parameters is performed in different ways according to the context indicated by dwMsg.

dwParam1

A parameter for the message.

dwParam2

A parameter for the message.

dwParam3

A parameter for the message.

Return Values

No return value.

Remarks

The call state when calling this function can be any state.

The service provider passes the HTAPILINE value supplied to TSPI_lineOpen as the htLine parameter. It includes the message identifier and parameters specific to the event.

This function differs from the callback function defined at the TAPI level in that it separates line and call parameters. Both parameters are used for some messages. The sets of messages that can be passed to this procedure differ slightly from the TAPI level. In particular, completion of asynchronously executing requests is reported through the ASYNC_COMPLETION callback instead of this one.

Requirements

  Windows NT/2000: Requires Windows NT 4.0 SP3 or later.
  Windows 95/98: Requires Windows 95 or later.
  Version: Requires TAPI 2.0 or later.
  Header: Declared in Tspi.h.

See Also

ASYNC_COMPLETION, TSPI_lineOpen