NLog在.NET Core Console Apps中的简单应用

什么是NLog?

NLog在GitHub的官网：https://github.com/NLog

NLog for .NET Core：https://github.com/NLog/NLog.Extensions.Logging

创建一个.NET Core Console 应用

使用CLI（Command Line Interface）创建一个example程序：

• dotnet new
• dotnet restore
• dotnet run

这些命令行的具体意思这里就不再赘述。

更改project.json的配置

主要是新增了NLog相关的配置：

• NLog的包引用；
• 程序发布时包含NLog的配置文件。

新增NLog的配置文件

在程序的根目录下新增NLog的配置文件：nlog.config

<?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="Warn"

      internalLogFile="internal-nlog.txt">

  <!-- define various log targets -->

  <targets>

    <!-- write logs to file -->

    <target xsi:type="File" name="allfile" fileName="nlog-all-${shortdate}.log"

                 layout="${longdate}|${event-properties:item=EventId.Id}|${logger}|${uppercase:${level}}|${message} ${exception}" />

    <target xsi:type="File" name="ownFile-web" fileName="nlog-own-${shortdate}.log"

             layout="${longdate}|${threadid}|${event-properties:item=EventId.Id}|${logger}|${uppercase:${level}}|  ${message} ${exception}" />

    <target xsi:type="Null" name="blackhole" />

  </targets>

  <rules>

    <!--Skip Microsoft logs and so log only own logs-->

    <logger name="Microsoft.*" minlevel="Trace" writeTo="blackhole" final="true" />

    <!--All logs, including from Microsoft-->

    <logger name="*" minlevel="Trace" writeTo="allfile" />

    <logger name="*" minlevel="Info" writeTo="ownFile-web" />

  </rules>

</nlog>

在Startup类中注册NLog的MiddleWare

 using Microsoft.AspNetCore.Builder;

 using Microsoft.AspNetCore.Hosting;

 using Microsoft.AspNetCore.Http;

 using Microsoft.Extensions.Logging;

 using NLog.Extensions.Logging;

 namespace ConsoleApplication

 {

     public class Startup

     {

         public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)

         {

             // Add NLog to ASP.NET Core

             loggerFactory.AddNLog();



             // configure nlog.config in your project root

             env.ConfigureNLog("nlog.config");



             app.Run(context =>

             {

                 return context.Response.WriteAsync("Hello World!!");

             });

         }

     }

 }

在入口类中记录日志

 using System.Threading;

 using Microsoft.AspNetCore.Hosting;

 using NLog;

 namespace ConsoleApplication

 {

     public class Program

     {

         private static Logger logger = LogManager.GetCurrentClassLogger();

         public static void Main(string[] args)

         {

             logger.Info("Server is running...");

             logger.Info(string.Format("Current Thead Id:{0}", Thread.CurrentThread.ManagedThreadId));

             var host = new WebHostBuilder().UseKestrel().UseStartup<Startup>().Build();

             host.Run();

         }

     }

 }

运行程序后会在主目录下生成2个日志文件：