C# NLog日志框架

1、首先下載NLog框架，在vs NuGet中搜索NLog，下載安裝NLog.Config

2、配置NLog.Config文件，我的常用配置如下

<?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}" encoding="UTF-8"/>

    <target xsi:type="Console" name="c"
            layout="${longdate} ${uppercase:${level}} ${message}" encoding="UTF-8"/>
    
  </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"/>
    <logger name="*" minlevel="Debug" writeTo="c"/>
  </rules>
</nlog>

3、寫靜態日志類LogUtil

  public class LogUtils
    {
        private static readonly Logger log = LogManager.GetLogger("*");
        /// <summary>
        /// 保存info級別的信息
        /// </summary>
        /// <param name="message"></param>
        public static void infoWrite(string message)
        {
            log.Info(message);
        }
        /// <summary>
        /// 保存info級別的信息
        /// </summary>
        /// <param name="className">類名</param>
        /// <param name="methodName">方法名</param>
        /// <param name="content">日志內容</param>
        public static void infoWrite(string className, string methodName, string content)
        {
            string message = "className:{" + className + "}, methodName:{" + methodName + "}, content:{" + content + "}";
            log.Info(message);
        }


        /// <summary>
        /// 保存error級別信息
        /// </summary>
        /// <param name="error"></param>
        public static void errorWrite(string error)
        {
            log.Error(error);
        }

        /// <summary>
        /// 保存error級別信息
        /// </summary>
        /// <param name="className">類名</param>
        /// <param name="methodName">方法名</param>
        /// <param name="content">日志內容</param>
        public static void errorWrite(string className, string methodName, string content)
        {
            string message = "className:{" + className + "}, methodName:{" + methodName + "}, content:{" + content + "}";
            log.Error(message);
        }

        /// <summary>
        /// 保存debug級別信息
        /// </summary>
        /// <param name="message"></param>
        public static void debugWrite(string message)
        {
            log.Debug(message);
        }

        /// <summary>
        /// 保存debug級別信息
        /// </summary>
        /// <param name="className">類名</param>
        /// <param name="methodName">方法名</param>
        /// <param name="content">日志內容</param>
        public static void debugWrite(string className, string methodName, string content)
        {
            string message = "className:{" + className + "}, methodName:{" + methodName + "}, content:{" + content + "}";
            log.Debug(message);
        }

        /// <summary>
        /// 刪除2個月前的日志文件
        /// </summary>
        public static void deleteLogFile(string logPath)
        {          
            if (!Directory.Exists(logPath))
            {
                return;
            }
            DirectoryInfo folder = new DirectoryInfo(logPath);
            FileInfo[] files = folder.GetFiles("*.log");
            if (files == null)
            {
                return;
            }

            foreach (FileInfo file in files)
            {
                //文件創建時間
                DateTime fileCreateTime = file.LastWriteTime;
                //當前時間
                DateTime now = DateTime.Now;
                int createMonth = fileCreateTime.Month;
                int nowMonth = now.Month;

                int distance = nowMonth - createMonth;
                distance = distance >= 0 ? distance : (distance + 12);

                if (distance < 3)
                {
                    //小於三個月不刪除
                    continue;
                }

                try
                {
                    File.Delete(file.FullName);
                }
                catch
                {
                    throw new Exception("刪除日志文件出現異常");
                }

            }
        }

    }