The lineGetMessage function returns the next TAPI message that is queued for delivery to an application that is using the Event Handle notification mechanism (see lineInitializeEx for further details).
LONG lineGetMessage( HLINEAPP hLineApp, LPLINEMESSAGE lpMessage, DWORD dwTimeout );
Pointer to a LINEMESSAGE structure. Upon successful return from this function, the structure contains the next message that had been queued for delivery to the application.
Time-out interval, in milliseconds. The function returns if the interval elapses, even if no message can be returned. If dwTimeout is zero, the function checks for a queued message and returns immediately. If dwTimeout is INFINITE, the function's time-out interval never elapses.
Returns zero if the request succeeds or a negative error number if an error occurs. Possible return values are:
LINEERR_INVALAPPHANDLE, LINEERR_OPERATIONFAILED, LINEERR_INVALPOINTER, LINEERR_NOMEM.
If the lineGetMessage function has been called with a non-zero timeout and the application calls lineShutdown on another thread, this function returns immediately with LINEERR_INVALAPPHANDLE.
If the timeout expires (or was zero) and no message could be fetched from the queue, the function returns with the error LINEERR_OPERATIONFAILED.