IDviInvocation* invocation = // obtain an IDviInvocation object DviInvocationResponse response(invocation); DviInputStream stream = invocation->InvocationReadStart(); if (stream == NULL) { response.SetErrorResponse(401); return; }In this example, we obtain an IDviInvocation object, create a DviInvocationResponse object to send a response, and then call InvocationReadStart to begin reading an input parameter. If the stream is null, we set an error response and return. Package Library: The package library being used in this code example is the DLNA C++ package library, which provides the IDviInvocation interface and related functions for interacting with DLNA devices.