创建一个.Net 6 Demo项目

引入NLog包

添加项目配置文件nlog.config

<?xml version="1.0" encoding="utf-8"?><nlog xmlns="; xsi:schemaLocation="NLog NLog.xsd"      xmlns:xsi=";      autoReload="true" >    <!-- the targets to write to -->    <targets>        <!--单个文件过大会导致写入效率下降，可配置单个文件的最大容量-->        <target name="File" xsi:type="AsyncWrapper" queueLimit="5000" overflowAction="Discard">            <target xsi:type="File"                    fileName="${basedir}/logs/${shortdate}.log"                    layout="${date:yyyy-MM-dd HH\:mm\:ss} ${level:uppercase=true} ${event-context:item=Action} ${message} ${event-context:item=Amount} ${stacktrace}"                    archiveAboveSize="10240"                    archiveEvery="Day"                    />        </target>        <!-- write logs to file -->        <!--<target xsi:type="File" name="logfile" fileName="c:\temp\console-example.log"                layout="${longdate}|${level}|${message} |${all-event-properties} ${exception:format=tostring}" />-->        <!--<target xsi:type="Console" name="logconsole"                layout="${longdate}|${level}|${message} |${all-event-properties} ${exception:format=tostring}" />-->    </targets>    <!-- rules to map from logger name to target -->    <rules>        <!--<logger name="*" levels="Debug,Info,Warn,Error" writeTo="File" />-->        <logger name="*" minlevel="Debug" maxlevel="Error" writeTo="File" />    </rules></nlog>

layout布局：

${longdate} 格式：2022-01-21 17:00:28.4860

后面的毫秒不是我想要的，可以自定义：date:yyyy-MM-dd HH\:mm\:ss

NLog等级

Trace：最常见的记录信息，一般是普通输出

Debug：同样是记录信息，出现的频率比Trace少，一般是调试程序

Info：信息类型的消息

Warn：警告消息

Error：错误消息

自上而下，等级递增

指定特定等级：level="Warn"

指定多个等级：levels="Debug,Info" 以逗号分隔

指定等级范围：minlevel="Info" maxlevel="Error"

<rules>    <!--<logger name="*" levels="Debug,Info,Warn,Error" writeTo="File" />-->    <logger name="*" minlevel="Debug" maxlevel="Error" writeTo="File" /></rules> 

添加工具类 Logger

using NLog;namespace TestNet6.Utilities{    public class Logger    {        NLog.Logger _logger { get; set; }        private Logger(NLog.Logger logger)        {            _logger = logger;        }        public Logger(string name) : this(LogManager.GetLogger(name))        {        }        public static Logger Default { get; private set; }        static Logger()        {            Default = new Logger(LogManager.GetCurrentClassLogger());        }        #region Dedub        public void Debug(string msg, params object[] args)        {            _logger.Debug(msg, args);        }        public void Debug(string msg, Exception e)        {            _logger.Debug(e, msg);        }        #endregion        #region Info        public void Info(string msg, params object[] args)        {            _logger.Info(msg, args);        }        public void Info(string msg, Exception e)        {            _logger.Info(e, msg);        }        #endregion        #region Trace        public void Trace(string msg, params object[] args)        {            _logger.Trace(msg, args);        }        public void Trace(string msg, Exception e)        {            _logger.Trace(e, msg);        }        #endregion        #region Warn        public void Warn(string msg, params object[] args)        {            _logger.Warn(msg, args);        }        public void Warn(string msg, Exception e)        {            _logger.Warn(e, msg);        }        #endregion        #region Error        public void Error(string msg, params object[] args)        {            _logger.Error(msg, args);        }        public void Error(string msg, Exception e)        {            _logger.Error(e, msg);        }        #endregion    }}

添加测试Controller

using Microsoft.AspNetCore.Mvc;using TestNet6.Utilities;namespace TestNet6.Controllers{    public class TestController : Controller    {        public ActionResult Index()        {            return View();        }        public string Test()        {            Logger.Default.Info("", Request);            return "Test String";        }    }}

最后为了让路由有效，还需要添加路由映射

var builder = WebApplication.CreateBuilder(args);// Add services to the container.builder.Services.AddRazorPages();var app = builder.Build();// Configure the HTTP request pipeline.if (!app.Environment.IsDevelopment()){    app.UseExceptionHandler("/Error");    // The default HSTS value is 30 days. You may want to change this for production scenarios, see .    app.UseHsts();}app.UseHttpsRedirection();app.UseStaticFiles();app.UseRouting();app.UseAuthorization();app.MapRazorPages();//添加路由映射app.MapControllerRoute(name: "default", pattern: "{controller=Home}/{action=Index}/{id?}");app.Run();

OK，运行测试