NLog 简单说会用

官网: https://nlog-project.org

使用概括

整理在 ASP.NET Core 上的简单使用. 使用步骤为:

1. 安装依赖 (NLog.Web.AspNetCore, NLog).
2. 准备配置文件 (nlog.config), 这个是重点.
3. 更新 Program.cs, 启用用 NLog.
4. 在需要使用日志的位置注入 ILogger 即可.

对于 ASP.NET 中怎么使用, GitHub 文档 有详细描述. 上述步骤即为整理的步骤.

• 配置文档
• 配置案例

简要说明

1. 安装依赖

安装两个依赖包:

<ItemGroup>
  <PackageReference Include="NLog.Web.AspNetCore" Version="5.*" />
  <PackageReference Include="NLog" Version="5.*" />
</ItemGroup>

然后执行命令: dotnet restore. 或者使用命令安装.

NuGet 链接:

• NLog.Web.AspNetCore
• NLog

dotnet add package NLog --version 5.2.7
dotnet add package NLog.Web.AspNetCore --version 5.3.7

2. 准备配置文件

在根目录下创建文件 nlog.config, 它是一个 XML 文件:

GitHub 链接

一般这个文件直接拷贝, 修改一下使用. 可参考下面的配置:

<?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="logs/nlog-AspNetCore-all.log"
				maxArchiveDays="0"
				maxArchiveFiles="0"
				archiveEvery="Day"
				enableArchiveFileCompression="true"
				archiveNumbering="Date"
				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="logs/nlog-AspNetCore-own.log"
				maxArchiveDays="0"
				maxArchiveFiles="0"
				archiveEvery="Day"
				enableArchiveFileCompression="true"
				archiveNumbering="Date"
				layout="${longdate}|${event-properties:item=EventId:whenEmpty=0}|${level:uppercase=true}|${logger}|${message} ${exception:format=tostring}|url: ${aspnet-request-url}|action: ${aspnet-mvc-action}" />

		<!--Console Target for hosting lifetime messages to improve Docker / Visual Studio startup detection -->
		<target xsi:type="Console" name="lifetimeConsole" layout="${MicrosoftConsoleLayout}" />
	</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>

3. 在 Program. cs 中注册 NLog

using NLog;
using NLog.Web;

// Early init of NLog to allow startup and exception logging, before host is built
var logger = NLog.LogManager.Setup().LoadConfigurationFromAppSettings().GetCurrentClassLogger();
logger.Debug("init main");

try {
  // 原有代码
  #region 配置日志模块
  // NLog: Setup NLog for Dependency injection
  builder.Logging.ClearProviders();
  builder.Host.UseNLog();
  #endregion
  // ...
}
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();
}

在各个控制器中需要使用的时候, 即可通过构造函数注入即可.