1、先项目中包管理 安装

2、在.net core 项目中Program.cs文件增加

  Host.CreateDefaultBuilder(args)
                    .ConfigureLogging((context, logging) => {
                        logging.ClearProviders();
                    })
                    .ConfigureWebHostDefaults(webBuilder =>
                            {
                                webBuilder.UseStartup();
                            }).UseNLog()
                    .UseWindowsService();

3、全局的使用

private static Logger logger = LogManager.GetCurrentClassLogger();

4、多租户

        private static NLog.ILogger CreateNLogInstance(string basePath, string TenancyFID, string repositoryName)
        {
            NLog.ILogger logTemp;
            var path = SystemParas.AppBasePath + "\\MrNlog.config";
            NLog.LogFactory logFactory = new NLog.LogFactory();
            //动态构建NLog配置文件
            //logFactory.Configuration = CreateLoggingConfiguration(basePath, repositoryName);
            //从配置文件读取NLog配置文件 修改其保存得路径和归档文件
            logFactory.Configuration = new NLog.Config.XmlLoggingConfiguration(path, true, logFactory);
            var fTagert = logFactory.Configuration.FindTargetByName(TargetName);
            fTagert.FileName = basePath + "/Log/Mes-Server-Log ${date:format=yyyy-MM-dd-HH}.log";//${shortdate}/${level}
            if (fTagert.ArchiveFileName != null)
            {
                fTagert.ArchiveFileName = basePath + "/Log/archives/log.{#####}.txt";//归档文件名
                fTagert.ArchiveNumbering = ArchiveNumberingMode.DateAndSequence;
            }
            //NLog.Config.SimpleConfigurator.ConfigureForTargetLogging(target, LogLevel);
            var rule = logFactory.Configuration.LoggingRules.Where(x => x.Targets.Any(s => s.Name == TargetName)).FirstOrDefault();
            logTemp = logFactory.GetCurrentClassLogger();
            return logTemp;
        }

5、动态修改日志等级

 static private void SetNLogFactoryParams(LogFactory logFactory, int LogFileMaxSize)
        {
            var fileNotTarget = logFactory.Configuration.FindTargetByName(TargetName);
            if (fileNotTarget == null)
            {
                return;
            }
            //fileNotTarget.MaxArchiveDays = baseLogFileMaxNumber;
            //fileNotTarget.MaxArchiveFiles = LogFileMaxSize;
            var ruleNot = logFactory.Configuration.LoggingRules.Where(x => x.Targets.Any(s => s.Name == TargetName)).FirstOrDefault();
            if (ruleNot == null)
            {
                return;
            }
            if (logLevelEnm == LogLevelEnum.ALL)
            {
                ruleNot.EnableLoggingForLevel(LogLevel.Debug);
                ruleNot.EnableLoggingForLevel(LogLevel.Trace);
                ruleNot.EnableLoggingForLevel(LogLevel.Info);
                ruleNot.EnableLoggingForLevel(LogLevel.Warn);
                ruleNot.EnableLoggingForLevel(LogLevel.Error);
                ruleNot.EnableLoggingForLevel(LogLevel.Fatal);
            }
            else if (logLevelEnm == LogLevelEnum.INFO)
            {
                ruleNot.EnableLoggingForLevel(LogLevel.Info);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Trace);
                ruleNot.DisableLoggingForLevel(LogLevel.Warn);
                ruleNot.DisableLoggingForLevel(LogLevel.Error);
                ruleNot.DisableLoggingForLevel(LogLevel.Fatal);
            }
            else if (logLevelEnm == LogLevelEnum.WARN)
            {
                ruleNot.EnableLoggingForLevel(LogLevel.Warn);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Trace);
                ruleNot.DisableLoggingForLevel(LogLevel.Info);
                ruleNot.DisableLoggingForLevel(LogLevel.Error);
                ruleNot.DisableLoggingForLevel(LogLevel.Fatal);
            }
            else if (logLevelEnm == LogLevelEnum.DEBUG)
            {
                ruleNot.EnableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Trace);
                ruleNot.DisableLoggingForLevel(LogLevel.Info);
                ruleNot.DisableLoggingForLevel(LogLevel.Error);
                ruleNot.DisableLoggingForLevel(LogLevel.Fatal);
            }
            else if (logLevelEnm == LogLevelEnum.ERROR)
            {
                ruleNot.EnableLoggingForLevel(LogLevel.Error);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Trace);
                ruleNot.DisableLoggingForLevel(LogLevel.Info);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Fatal);
            }
            else if (logLevelEnm == LogLevelEnum.FATAL)
            {
                ruleNot.EnableLoggingForLevel(LogLevel.Fatal);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Trace);
                ruleNot.DisableLoggingForLevel(LogLevel.Info);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Error);
            }
            else if (logLevelEnm == LogLevelEnum.OFF)
            {
                ruleNot.EnableLoggingForLevel(LogLevel.Off);
                ruleNot.DisableLoggingForLevel(LogLevel.Fatal);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Trace);
                ruleNot.DisableLoggingForLevel(LogLevel.Info);
                ruleNot.DisableLoggingForLevel(LogLevel.Debug);
                ruleNot.DisableLoggingForLevel(LogLevel.Error);
            }

          // 只有加这个才会起效果

            logger.nLogger.Factory.ReconfigExistingLoggers();
        }

6、配置文件 MrNlog.config

      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
      autoReload="true"
      throwExceptions="true"
      internalLogLevel="Trace" internalLogFile="D:\temp\nlog-internal.log">
    
                         layout="${newline} ${longdate} ${uppercase:${level}} ${threadid} ${newline} Message: ${message} ${newline}}" encoding="utf-8"
                archiveEvery="Hour" archiveAboveSize="2097152"
                maxArchiveDays="1"
                maxArchiveFiles="2"/>