MicrosoftILoggerTarget - Reduce code complexity (#510)

Author: snakefoot

src/NLog.Extensions.Logging/Targets/MicrosoftILoggerTarget.cs

@@ -88,30 +88,39 @@ protected override void Write(LogEventInfo logEvent)
             if (!ilogger.IsEnabled(logLevel))
                 return;
 
+            var layoutMessage = RenderLogEvent(Layout, logEvent);
+
+            IDictionary<string, object> contextProperties = null;
+            if (ContextProperties.Count > 0 || IncludeMdlc || IncludeMdc || IncludeGdc)
+            {
+                contextProperties = GetContextProperties(logEvent);
+                if (contextProperties?.Count == 0)
+                    contextProperties = null;
+            }
+
+            var eventId = RenderEventId(logEvent);
+            ilogger.Log(logLevel, eventId, new LogState(logEvent, layoutMessage, contextProperties), logEvent.Exception, (s, ex) => LogStateFormatter(s));
+        }
+
+        private EventId RenderEventId(LogEventInfo logEvent)
+        {
             var eventId = default(EventId);
+
             if (EventId != null)
             {
                 var eventIdValue = RenderLogEvent(EventId, logEvent);
                 if (!string.IsNullOrEmpty(eventIdValue) && int.TryParse(eventIdValue, out int eventIdParsed) && eventIdParsed != 0)
                     eventId = new EventId(eventIdParsed);
             }
+
             if (EventName != null)
             {
                 var eventNameValue = RenderLogEvent(EventName, logEvent);
                 if (!string.IsNullOrEmpty(eventNameValue))
                     eventId = new EventId(eventId.Id, eventNameValue);
             }
 
-            var layoutMessage = RenderLogEvent(Layout, logEvent);
-            IDictionary<string, object> contextProperties = null;
-            if (ContextProperties.Count > 0 || IncludeMdlc || IncludeMdc || IncludeGdc)
-            {
-                contextProperties = GetContextProperties(logEvent);
-                if (contextProperties?.Count == 0)
-                    contextProperties = null;
-            }
-
-            ilogger.Log(ConvertToLogLevel(logEvent.Level), eventId, new LogState(logEvent, layoutMessage, contextProperties), logEvent.Exception, (s, ex) => LogStateFormatter(s));
+            return eventId;
         }
 
         private Microsoft.Extensions.Logging.ILogger CreateFromLoggerFactory(LogEventInfo logEvent)