步骤

1. 添加依赖

①Microsoft.Extensions.DependencyInjection

②NLog.Extensions.Logging（或Microsoft.Extensions.Logging.___）

Tutorial · NLog/NLog Wiki · GitHub

2.添加nlog.config文件(默认名称, 可改为其他名称, 但需要另行配置)

文件的基础格式可从此处获取: Tutorial · NLog/NLog Wiki · GitHubNLog - Advanced and Structured Logging for Various .NET Platforms - Tutorial · NLog/NLog Wikihttps://github.com/NLog/NLog/wiki/Tutorial#configure-nlog-targets-for-output格式参考(关于config文件的说明在注释部分):

<?xml version="1.0" encoding="utf-8" ?>
<!-- XSD manual extracted from package NLog.Schema: https://www.nuget.org/packages/NLog.Schema-->
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xsi:schemaLocation="NLog NLog.xsd"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"autoReload="true"internalLogFile="logs/console-example-internal.log"internalLogLevel="Info" ><!-- the targets to write to --><targets><!-- write logs to file --><!-- archiveAboveSize: 日志文件的最大体积(字节数)|maxArchiveFiles: 日志文件的最大数量|maxArchiveDays: 日志文件的最大天数 --><target xsi:type="File" name="logfile" fileName="logs/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><!-- 从上至下依次匹配 --><!-- name: 匹配规则(类名)|minlevel: 最小日志输出等级|maxlevel: 最大日志输出等级|writeTo: 日志输出文件|final=true: 若匹配成功则不再向下匹配 --><logger name="*" minlevel="Trace" writeTo="logfile,logconsole"/></rules>
</nlog>

3.将nlog.config文件设置为"始终复制"或在项目设置页中将"Never"改为"Always"

示例

Program.cs

internal class Program
{static void Main(string[] args){ServiceCollection services = new();services.AddLogging(logBuilder=> {//logBuilder.AddConsole();                    // Microsoft.Extensions.Logging//logBuilder.SetMinimumLevel(LogLevel.Debug); // Microsoft.Extensions.LogginglogBuilder.AddNLog();});services.AddScoped<Example_1>();using ServiceProvider serviceProvider = services.BuildServiceProvider();Example_1 example_1 = serviceProvider.GetRequiredService<Example_1>();example_1.Start();}
}

Example_1.cs

internal class Example_1
{ILogger<Example_1> logger;public Example_1(ILogger<Example_1> logger){this.logger = logger;}public void Start(){logger.LogDebug("运行中...");try{File.ReadAllText("A:\\text.txt");logger.LogDebug("文件读取成功");}catch (Exception e){logger.LogError(e, "发生错误");}logger.LogDebug("结束");}
}

运行效果