LINE_REPLY

The TAPI LINE_REPLY message is sent to report the results of function calls that completed asynchronously.

LINE_REPLY
hDevice = (DWORD) 0;
dwCallbackInstance = (DWORD) hCallback;
dwParam1 = (DWORD) idRequest;
dwParam2 = (DWORD) Status;
dwParam3 = (DWORD) 0;

Parameters

hDevice

Not used.

dwCallbackInstance

Returns the application's callback instance.

dwParam1

The request identifier for which this is the reply.

dwParam2

The success or error indication. The application should cast this parameter into a LONG. Zero indicates success; a negative number indicates an error.

dwParam3

Unused.

Return Values

No return value.

Remarks

Functions that operate asynchronously return a positive request identifier value to the application. This request identifier is returned with the reply message to identify the request that was completed. The other parameter for the LINE_REPLY message carries the success or failure indication. Possible errors are the same as those defined by the corresponding function. This message cannot be disabled.

In some cases, an application may fail to receive the LINE_REPLY message corresponding to a call to an asynchronous function. This occurs if the corresponding call handle is deallocated before the message has been received.

Note  When an application invokes any asynchronous operation that writes data back into application memory, the application must keep that memory available for writing until a LINE_REPLY or LINE_GATHERDIGITS message is received.

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 Tapi.h.

See Also

LINE_GATHERDIGITS