public void BeginEchoString(String aValue, CallbackAsyncComplete aCallback) { Invocation invocation = iService.Invocation(iActionEchoString, aCallback); int inIndex = 0; invocation.AddInput(new ArgumentString((ParameterString)iActionEchoString.InputParameter(inIndex++), aValue)); int outIndex = 0; invocation.AddOutput(new ArgumentString((ParameterString)iActionEchoString.OutputParameter(outIndex++))); iService.InvokeAction(invocation); }