1.Nuget 引入

NLog

NLog.Web.AspNetCore

NLog.Database(写入数据库使用)

2.创建nlog.config

注意数据库连接字符串需要配置TrustServerCertificate=True;不然会有认证问题

<?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"/>

		<add assembly="NLog.Database"/>

	</extensions>

	<!-- the targets to write to -->

	<targets>

		<target name="AllDatabase" xsi:type="Database"

            dbProvider="Microsoft.Data.SqlClient.SqlConnection, Microsoft.Data.SqlClient"

            connectionString="Data Source=.;Initial Catalog=LogTest;Persist Security Info=True;User ID=sa;Password=123;Encrypt=True;TrustServerCertificate=True;"

            commandText="insert into dbo.NLogManager (Application, Logged, Level, Message,Logger, CallSite, Exception) values (@Application, @Logged, @Level, @Message,@Logger, @Callsite, @Exception);">

			<parameter name="@application" layout="AspNetCoreNlog" />

			<parameter name="@logged" layout="${date}" />

			<parameter name="@level" layout="${level}" />

			<parameter name="@message" layout="${message}" />

			<parameter name="@logger" layout="${logger}" />

			<parameter name="@callSite" layout="${callsite:filename=true}" />

			<parameter name="@exception" layout="${exception:tostring}" />

		</target>

		<!-- 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>

	<!-- rules to map from logger name to target -->

	<rules>

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

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

		<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>

builder.Logging.ClearProviders();//删除所有其他关于日志的配置

builder.Logging.SetMinimumLevel(LogLevel.Trace);//指定级别

builder.Host.UseNLog();

private readonly ILogger<HomeController> _logger;

private readonly ILoggerFactory _loggerfactoary;

public HomeController(ILogger<HomeController> logger, ILoggerFactory loggerfactoary)

{

  _logger = logger;

  _logger.LogInformation($"logger{this.GetType().FullName}被构造");

  _loggerfactoary = loggerfactoary;

  ILogger<HomeController> _logger2 = _loggerfactoary.CreateLogger<HomeController>();

  _logger2.LogInformation($"logger2{this.GetType().FullName}被构造");

}