.Net Core配置Nlog

今天我们来使用官网为.Net Core来配置Nlog

一. 首先还是老规矩先下载Nlog的NuGet包，我们需要下载两个，第一个是：NLog，第二个是：NLog.Web.AspNetCore。都下载最新版就可以

二. 配置nlog.config文件

和以前一样，也需要创建一个nlog.config文件，在文件中输入以下代码，其中绿色代码是文件保存的位置我们可以根据需要更改

<?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="c:\temp\internal-nlog-AspNetCore.txt">

  <!-- enable asp.net core layout renderers -->
  <extensions>
    <add assembly="NLog.Web.AspNetCore"/>
  </extensions>

  <!-- the targets to write to -->
  <targets>
    <!-- File Target for all log messages with basic details -->
    <target xsi:type="File" name="allfile" fileName="c:\temp\nlog-AspNetCore-all-${shortdate}.log"
            layout="${longdate}|${event-properties:item=EventId_Id:whenEmpty=0}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}" />

    <!-- File Target for own log messages with extra web details using some ASP.NET core renderers -->
    <target xsi:type="File" name="ownFile-web" fileName="c:\temp\nlog-AspNetCore-own-${shortdate}.log"
            layout="${longdate}|${event-properties:item=EventId_Id:whenEmpty=0}|${uppercase:${level}}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}|${callsite}| body: ${aspnet-request-posted-body}" />

    <!--Console Target for hosting lifetime messages to improve Docker / Visual Studio startup detection -->
    <target xsi:type="Console" name="lifetimeConsole" layout="${level:truncate=4:lowercase=true}: ${logger}[0]${newline}      ${message}${exception:format=tostring}" />
  </targets>

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

    <!--Output hosting lifetime messages to console target for faster startup detection -->
    <logger name="Microsoft.Hosting.Lifetime" minlevel="Info" writeTo="lifetimeConsole, ownFile-web" final="true" />

    <!--Skip non-critical Microsoft logs and so log only own logs (BlackHole) -->
    <logger name="Microsoft.*" maxlevel="Info" final="true" />
    <logger name="System.Net.Http.*" maxlevel="Info" final="true" />
    
    <logger name="*" minlevel="Trace" writeTo="ownFile-web" />
  </rules>
</nlog>

三. 更新program.cs文件

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using System;
using NLog.Web;

namespace ASP.NET_Core_5_NLog_Example
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var logger = NLogBuilder.ConfigureNLog("nlog.config").GetCurrentClassLogger();
            try
            {
                logger.Debug("init main");
                CreateHostBuilder(args).Build().Run();
            }
            catch (Exception exception)
            {
                //NLog: catch setup errors
                logger.Error(exception, "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();
            }
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                })
                .ConfigureLogging(logging =>
                {
                    logging.ClearProviders();
                    logging.SetMinimumLevel(LogLevel.Trace);
                })
                .UseNLog();  // NLog: Setup NLog for Dependency injection
    }
}

四. 配置appsettings.json文件(这一步是进行与否都可以的)

{
  "Logging": {
    "LogLevel": {
      "Default": "Trace",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*"
}

五. 注入 ILogger

using Microsoft.Extensions.Logging;

public class HomeController : Controller
{
    private readonly ILogger<HomeController> _logger;

    public HomeController(ILogger<HomeController> logger)
    {
        _logger = logger;
        _logger.LogDebug(1, "NLog injected into HomeController");
    }

    public IActionResult Index()
    {
        _logger.LogInformation("Hello, this is the index!");
        return View();
    }

以上就是官网为.Net Core来配置Nlog的方法