ASP.NET Core中使用日志组件NLog

上一篇文章描述了如何在ASP.NET Core中使用Log4Net记录日志。本篇将使用另外一个组件NLog在ASP.NET Core中记录日志。

1.引入程序集 NLog.Web.AspNetCore（NuGet中直接添加）

2.增加配置文件，配置Nlog生效

3.注入得到Nlog生效，写文本日志

4.引入数据库相关程序集  System.Data.SqlClient

5.初始化数据库日志表，配置写日志到数据库

NLog对应的XML格式的配置文件如下：

<?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"
      xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
      autoReload="true"
      throwExceptions="false"
      internalLogLevel="Off" internalLogFile="c:\temp\nlog-internal.log">

  <!-- optional, add some variables
  https://github.com/nlog/NLog/wiki/Configuration-file#variables
  -->
  <variable name="myvar" value="myvalue"/>

  <!--
  See https://github.com/nlog/nlog/wiki/Configuration-file
  for information on customizing logging rules and outputs.
   -->
  <targets>
    <!--
    add your targets here
    See https://github.com/nlog/NLog/wiki/Targets for possible targets.
    See https://github.com/nlog/NLog/wiki/Layout-Renderers for the possible layout renderers.
    -->
    <target name="AllDatabase" xsi:type="Database"
          dbProvider="System.Data.SqlClient.SqlConnection, System.Data.SqlClient"
          connectionString="Data Source=.\SQLEXPRESS;Initial Catalog=LogManager;Persist Security Info=True;User ID=sa;Password=a123456!"
          commandText="insert into dbo.NLog (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>

    <target xsi:type="File" name="allfile" fileName="NLog\nlog-all-${shortdate}.log"
            layout="${longdate}|${logger}|${uppercase:${level}}|${message} ${exception}" />
    <!--同样是将文件写入日志中，写入的内容有所差别，差别在layout属性中体现。写入日志的数量有差别，差别在路由逻辑中体现-->
    <target xsi:type="File" name="ownFile-web" fileName="NLog\nlog-my-${shortdate}.log"
             layout="${longdate}|${logger}|${uppercase:${level}}|${message} ${exception}" />
    <target xsi:type="Null" name="blackhole" />
    <!--
    Write events to a file with the date in the filename.
    <target xsi:type="File" name="f" fileName="${basedir}/logs/${shortdate}.log"
            layout="${longdate} ${uppercase:${level}} ${message}" />
    -->
  </targets>

  <rules>
    <logger name="*" minlevel="Trace" writeTo="AllDatabase" />
    <!-- add your logging rules here -->
    <!--路由顺序会对日志打印产生影响。路由匹配逻辑为顺序匹配。-->
    <!--All logs, including from Microsoft-->
    <logger name="*" minlevel="Trace" writeTo="allfile" />
    <!--Skip Microsoft logs and so log only own logs-->
    <!--以Microsoft打头的日志将进入此路由，由于此路由没有writeTo属性，所有会被忽略-->
    <!--且此路由设置了final，所以当此路由被匹配到时。不会再匹配此路由下面的路由。未匹配到此路由时才会继续匹配下一个路由-->
    <logger name="Microsoft.*" minlevel="Trace"  final="true" />
    <!--上方已经过滤了所有Microsoft.*的日志，所以此处的日志只会打印除Microsoft.*外的日志-->
    <logger name="*" minlevel="Trace" writeTo="ownFile-web" />
    <!--
    Write all events with minimal level of Debug (So Debug, Info, Warn, Error and Fatal, but not Trace)  to "f"
    <logger name="*" minlevel="Debug" writeTo="f" />
    -->
  </rules>
</nlog>

C#代码如下：

#region NLogin
{
    //Nuget引入：NLog.Web.AspNetCore
    //builder.Logging.AddNLog("CfgFile/NLog.config");
}
#endregion