1.NuGet中引用NLog外掛安裝

2、建立一個NLogHelper類例項化日誌函式

    public class NLogHelper 
    {
        private readonly Logger logger = LogManager.GetCurrentClassLogger();

        public void Debug(object message)
        {
            logger.Debug(message);
        }

        public void Debug(object message, Exception exception)
        {
            logger.Debug(exception, message.ToString());
        }

        public void Error(object message)
        {
            logger.Error(message);
        }

        public void Error(object message, Exception exception)
        {
            logger.Error(exception, message.ToString());
        }

        public void Fatal(object message)
        {
            logger.Fatal(message);
        }

        public void Fatal(object message, Exception exception)
        {
            logger.Fatal(exception, message.ToString());
        }

        public void Info(object message)
        {
            logger.Info(message);
        }

        public void Info(object message, Exception exception)
        {
            logger.Info(exception, message.ToString());
        }

        public void Warn(object message)
        {
            logger.Warn(message);
        }

        public void Warn(object message, Exception exception)
        {
            logger.Warn(exception, message.ToString());
        }
    }

　　3、建立NLog.config檔案

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
      autoReload="true"
      throwExceptions="false"
      internalLogLevel="Off" internalLogFile="c:\temp\nlog-internal.log">

  <!-- optional, add some variables
  https://github.com/nlog/NLog/wiki/Configuration-file#variables
  -->
  <variable name="myvar" value="myvalue"/>

  <!--
  See https://github.com/nlog/nlog/wiki/Configuration-file
  for information on customizing logging rules and outputs.
   -->
  <targets>

    <!--
    add your targets here
    See https://github.com/nlog/NLog/wiki/Targets for possible targets.
    See https://github.com/nlog/NLog/wiki/Layout-Renderers for the possible layout renderers.
    -->

    <!--
    Write events to a file with the date in the filename.
    <target xsi:type="File" name="f" fileName="${basedir}/logs/${shortdate}.log"
            layout="${longdate} ${uppercase:${level}} ${message}" />
    -->

	  <!-- info檔案配置  -->
	  <target name="info" xsi:type="File"  fileName="${basedir}/Logs/Info/${shortdate}/info.txt" maxArchiveFiles="30" 
			  layout="${longdate} | ${level:uppercase=false} | ${message} ${onexception:${exception:format=tostring} ${newline} ${stacktrace} ${newline}" />
	  <!-- error檔案配置  -->
	  <target name="error" xsi:type="File"	  fileName="${basedir}/Logs/Error/${shortdate}/error.txt"  maxArchiveFiles="30"
	          layout="${longdate} | ${level:uppercase=false} | ${message} ${onexception:${exception:format=tostring} ${newline} ${stacktrace} ${newline}" />
	  <!-- nlog檔案配置  -->
	  <target name="debug" xsi:type="File"	  fileName="${basedir}/Logs/debug/${shortdate}/debug.txt"  maxArchiveFiles="30"
	          layout="${longdate} | ${level:uppercase=false} | ${message} ${onexception:${exception:format=tostring} ${newline} ${stacktrace} ${newline}" />
	  
  </targets>

  <rules>
    <!-- add your logging rules here -->

    <!--
    Write all events with minimal level of Debug (So Debug, Info, Warn, Error and Fatal, but not Trace)  to "f"
    <logger name="*" minlevel="Debug" writeTo="f" />
    -->

	  <!-- log檔案配置  -->
	  <logger name="*" writeTo="DatabaseFile" />
	  <logger name="*" minlevel="Info" writeTo="info" />
	  <logger name="*" minlevel="Error" writeTo="error" />
	  <logger name="*" minlevel="Debug" writeTo="debug" />
	  <logger name="*" writeTo="console" />
	  
  </rules>
</nlog>