参见：https://github.com/NLog/NLog.Web/wiki/Getting-started-with-ASP.NET-Core-2
大致步骤：
- Nuget中引用NLog及NLog.Web.AspNetCore 4.5+
- 创建nlog.config文件，部分修改：
<?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" ?????autoReload="true" ?????internalLogLevel="info" ?????internalLogFile="logs\internal-nlog.txt"> ?<!-- enable asp.net core layout renderers --> ?<extensions> ???<add assembly="NLog.Web.AspNetCore"/> ?</extensions> ?<!-- the targets to write to --> ?<targets> ???<!-- write logs to file ?--> ???<target xsi:type="File" name="allfile" fileName="logs\nlog-all-${shortdate}.log" ???????????layout="${longdate}|${event-properties:item=EventId_Id}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}" /> ???<!-- another file log, only own logs. Uses some ASP.NET core renderers --> ???<target xsi:type="File" name="ownFile-web" fileName="logs\nlog-own-${shortdate}.log" ???????????layout="${longdate}|${event-properties:item=EventId_Id}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}" /> ?</targets> ?<!-- rules to map from logger name to target --> ?<rules> ???<!--All logs, including from Microsoft--> ???<logger name="*" minlevel="Trace" writeTo="allfile" /> ???<!--Skip non-critical Microsoft logs and so log only own logs--> ???<logger name="Microsoft.*" maxLevel="Info" final="true" /> ???<!-- BlackHole without writeTo --> ???<logger name="*" minlevel="Trace" writeTo="ownFile-web" /> ?</rules></nlog>- 右键nlog.config，属性，生成操作设为“内容”，复制到输出目录为“始终复制”
- Program.cs中：
var logger = NLog.Web.NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger(); ???????????try ???????????{ ???????????????logger.Debug("init main"); ???????????????var hostBuilder = CreateWebHostBuilder(args); ???????????????var host = hostBuilder.Build(); ???????????????host.Run(); ???????????} ???????????catch (Exception ex) ???????????{ ???????????????//NLog: catch setup errors ???????????????logger.Error(ex, "Stopped program because of exception"); ???????????????throw; ???????????} ???????????finally ???????????{ ???????????????// Ensure to flush and stop internal timers/threads before application-exit (Avoid segmentation fault on Linux) ???????????????NLog.LogManager.Shutdown(); ???????????}- 配置appsettings.json。注意在配置中的设置将覆盖代码中的SetMinimumLevel属性。所以要么删除“Default”使用代码中的配置，要么就要设置正确。
{ ???"Logging": { ???????"LogLevel": { ???????????"Default": "Trace", ???????????"Microsoft": "Information" ???????} ???}}注意：如你有多个环境，注意appsetings.Development.json的配置。
- 使用：
using Microsoft.Extensions.Logging;public class HomeController : Controller{ ???private readonly ILogger<HomeController> _logger; ???public HomeController(ILogger<HomeController> logger) ???{ ???????_logger = logger; ???} ???public IActionResult Index() ???{ ???????_logger.LogInformation("Index page says hello"); ???????return View(); ???}- 结果查看。如你的配置与我一致，则在项目的logs文件夹会存在internal-nlog.txt文件。在bin\Debug\netcoreapp2.1\logs目录下会以日期存在输出日志。
.Net Core使用NLog记录日志
原文地址：https://www.cnblogs.com/ceci/p/9173037.html