protected override void Append()

in src/log4net/Appender/EventLogAppender.cs [384:476]
78 lines of code
15 McCabe index (conditional complexity)

		protected override void Append(LoggingEvent loggingEvent) 
		{
			//
			// Write the resulting string to the event log system
			//
			int eventID = m_eventId;

			// Look for the EventID property
			object eventIDPropertyObj = loggingEvent.LookupProperty("EventID");
			if (eventIDPropertyObj != null)
			{
				if (eventIDPropertyObj is int)
				{
					eventID = (int)eventIDPropertyObj;
				}
				else
				{
					string eventIDPropertyString = eventIDPropertyObj as string;
                    if (eventIDPropertyString == null)
                    {
                        eventIDPropertyString = eventIDPropertyObj.ToString();
                    }
					if (eventIDPropertyString != null && eventIDPropertyString.Length > 0)
					{
						// Read the string property into a number
						int intVal;
						if (SystemInfo.TryParse(eventIDPropertyString, out intVal))
						{
							eventID = intVal;
						}
						else
						{
							ErrorHandler.Error("Unable to parse event ID property [" + eventIDPropertyString + "].");
						}
					}
				}
			}

            short category = m_category;
            // Look for the Category property
            object categoryPropertyObj = loggingEvent.LookupProperty("Category");
            if (categoryPropertyObj != null)
            {
                if (categoryPropertyObj is short)
                {
                    category = (short) categoryPropertyObj;
                }
                else
                {
                    string categoryPropertyString = categoryPropertyObj as string;
                    if (categoryPropertyString == null)
                    {
                        categoryPropertyString = categoryPropertyObj.ToString();
                    }
                    if (categoryPropertyString != null && categoryPropertyString.Length > 0)
                    {
                        // Read the string property into a number
                        short shortVal;
                        if (SystemInfo.TryParse(categoryPropertyString, out shortVal))
                        {
                            category = shortVal;
                        }
                        else
                        {
                            ErrorHandler.Error("Unable to parse event category property [" + categoryPropertyString + "].");
                        }
                    }
                }
            }

			// Write to the event log
			try
			{
				string eventTxt = RenderLoggingEvent(loggingEvent);

				// There is a limit of about 32K characters for an event log message
				if (eventTxt.Length > MAX_EVENTLOG_MESSAGE_SIZE)
				{
					eventTxt = eventTxt.Substring(0, MAX_EVENTLOG_MESSAGE_SIZE);
				}

				EventLogEntryType entryType = GetEntryType(loggingEvent.Level);

				using(SecurityContext.Impersonate(this))
				{
					EventLog.WriteEntry(m_applicationName, eventTxt, entryType, eventID, category);
				}
			}
			catch(Exception ex)
			{
				ErrorHandler.Error("Unable to write to event log [" + m_logName + "] using source [" + m_applicationName + "]", ex);
			}
		}