<"1.0" encoding="utf-8" "http://www.nlog-project.org/schemas/NLog.xsd"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  autoReload="true"
  internalLogLevel="Warn"
  internalLogFile="internal-nlog.txt">

 <!--define various log targets-->
 <targets>

 <!--write logs to file-->
 <target xsi:type="File" name="allfile" fileName="Logs/service-${shortdate}.log"
     layout="${longdate}|${logger}|${uppercase:${level}}|${message} ${exception}" />

 </targets>

 <rules>
 <!--All logs, including from Microsoft-->
 <logger name="*" minlevel="Trace" writeTo="allfile" />
 </rules>
</nlog>

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactor)
{
 //使用Nlog
 loggerFactor.AddNLog();
 //引入配置文件
 env.ConfigureNLog("nlog.config");
 if (env.IsDevelopment())
 {
  app.UseDeveloperExceptionPage();
 }
 else
 {
  app.UseExceptionHandler("/Error");
 }
 app.UseStaticFiles();
 app.UseCookiePolicy();

 app.UseMvc();
}

public class IndexModel : PageModel
{
 private ILogger<IndexModel> _logger;
 public IndexModel(ILogger<IndexModel> logger)
 {
  _logger = logger;
 }
 public string Customer { get; set; }
 public void OnGet()
 {
  _logger.LogWarning("111111111111111111111");
  Customer = "123456";
 }
}

private static Logger Logger = LogManager.GetCurrentClassLogger();
public static void Main(string[] args)
{
 Logger.Error("22222222222222222222222222222");
 Logger.Info("333333333333333333333333333333");
}

<"1.0" encoding="utf-8" "ConsoleAppender" type="log4net.Appender.ConsoleAppender">
  <layout type="log4net.Layout.PatternLayout" value="%date [%thread] %-5level %logger - %message%newline" />
 </appender>

 <appender name="FileAppender" type="log4net.Appender.FileAppender">
  <file value="log-file.log" />
  <appendToFile value="true" />
  <layout type="log4net.Layout.PatternLayout">
  <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
  </layout>
 </appender>

 <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
  <file value="logs/" /> 
  <appendToFile value="true" />
  <rollingStyle value="Date" />
  <staticLogFileName value="false" />
  <datePattern value="yyyy-MM-dd'.log'" />
  <maxSizeRollBackups value="7" />
  <maximumFileSize value="1MB" />
  <layout type="log4net.Layout.PatternLayout">
  <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
  </layout>
 </appender>

 <!-- Setup the root category, add the appenders and set the default level -->
 <root>
  <level value="ALL" />
  <appender-ref ref="ConsoleAppender" />
  <appender-ref ref="FileAppender" />
  <appender-ref ref="RollingLogFileAppender" />
 </root>

 </log4net>
</configuration>

public static ILoggerRepository repository { get; set; }

public Startup(IConfiguration configuration)
{
 Configuration = configuration;
 //log4net
 repository = LogManager.CreateRepository("NETCoreRepository");
 //指定配置文件
 XmlConfigurator.Configure(repository, new FileInfo("log4net.config"));
}

private ILog log = LogManager.GetLogger(Startup.repository.Name, typeof(ValuesController));

[HttpGet]
public ActionResult<IEnumerable<string Get()
{
 log.Info(1111111111111111111);
 return new string[] { "value1", "value2" };
}

ILoggerRepository repository = LogManager.CreateRepository("NETCoreRepository");

XmlConfigurator.Configure(repository, new FileInfo("log4net.config"));

ILog log = LogManager.GetLogger(repository.Name,"NETCorelog4net");
 
log.Info("test log");