在.NET 6 下简单使用NLog

Nlog是.NET几大成熟的日志框架,可以配置写入到文件,也可以配置写入到数据库,从.net framework开始就比较成熟了。到了.NET Core时代,NLog也紧跟时代,现在已经更新到5.0版本。本文将讲述NLog在.NET6下的简单使用。

一、环境准备

新建一个.NET6的MVC项目,并在nuget添加NLog包,由于是asp.net mvc项目需要如下包NLog.Web.AspNetCore。安装命令如下:.

install-package NLog.Web.AspNetCore

二、添加项目配置文件nlog.config

点击项目右键添加nlog.config文件,然后复制下面的Xml内容

<?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>
    <!--配置文件位置,配置为项目生成目录,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} ${stacktrace}"                    archiveAboveSize="10240"                    archiveEvery="Day"                    />    </target>
    <!--配置文件位置,下面是默认的配置,存放的位置为C盘-->    <!-- File Target for all log messages with basic details -->    <!--<target xsi:type="File" name="allfile" fileName="c:\temp\nlog-AspNetCore-all-${shortdate}.log"        layout="${longdate}|${event-properties:item=EventId:whenEmpty=0}|${level:uppercase=true}|${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:whenEmpty=0}|${level:uppercase=true}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}|${callsite}" />
    --><!--Console Target for hosting lifetime messages to improve Docker / Visual Studio startup detection --><!--    <target xsi:type="Console" name="lifetimeConsole" layout="${MicrosoftConsoleLayout}" />-->  </targets>
  <!-- 配置日志级别 -->  <rules>
    <logger name="*" minlevel="Debug" maxlevel="Error" writeTo="File" />    <!-- 下面是默认的配置-->    <!--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>

layout是配置日期等布局格式。

rules节点是配置日志的级别,跟微软默认的日志级别类似。如果使用appsettings.json的日志级别需要配置RemoveLoggerFactoryFilter = false

在.NET 6 下简单使用NLog

三、在Program.cs添加Nlog组件

using NLog;using NLog.Web;
var logger = NLog.LogManager.Setup().LoadConfigurationFromAppSettings().GetCurrentClassLogger();logger.Debug("init main");try{
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.builder.Services.AddControllersWithViews();
// NLog:注册Nlog组件builder.Logging.ClearProviders();builder.Host.UseNLog();
var app = builder.Build();
// Configure the HTTP request pipeline.if (!app.Environment.IsDevelopment()){    app.UseExceptionHandler("/Home/Error");}app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.MapControllerRoute(    name: "default",    pattern: "{controller=Home}/{action=Index}/{id?}");
app.Run();}catch (Exception exception){    // NLog: 抓取全局错误    logger.Error(exception, "Stopped program because of exception");    throw;}finally{    // 确保在跑出异常停止线程 (避免在linux中报错)    NLog.LogManager.Shutdown();}

四、日志使用

配置完成就可以使用Nlog了,跟默认的日志注入一样,代码如下:

        private readonly ILogger<HomeController> _logger;
        public HomeController(ILogger<HomeController> logger)        {            _logger = logger;        }        public IActionResult Index()        {            _logger.LogInformation("Hello,这是主页面!");            return View();        }

五、查看日志

以上工作完成后就可以在生成环境里logs里的日志文件了。

在.NET 6 下简单使用NLog

篇幅有限具体说明请看官方文档

https://github.com/NLog/NLog

源码链接:

https://pan.baidu.com/s/1T8HU06y4C1JxzRty5AAHEg?pwd=0qae