.NET CORE 使用log4net

需要从NuGet 中安装log4net,直接安装

log4net
新建一个log4net 的配置文件（xml文件），可以任意名字，例如起名叫log4net.config
把配置项填写进去

<?xml version="1.0" encoding="utf-8"?>
<configuration>

  <!-- This section contains the log4net configuration settings -->
  <log4net>
    <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
      <layout type="log4net.Layout.PatternLayout" value="%date [%thread] %-5level %logger - %message%newline" />
    </appender>
    <appender name="FileAppender" type="log4net.Appender.FileAppender">
      <file value="log-file.log" />
      <appendToFile value="true" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
      </layout>
    </appender>
    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender,log4net">
      <file value="Log/" />
      <appendToFile value="true" />
      <rollingStyle value="Composite" />
      <RollingStyle value="Date" />
      <staticLogFileName value="false" />
      <datePattern value="yyyy.MM.dd'.log'" />
      <!--<maxSizeRollBackups value="10" />
      <maximumFileSize value="1MB" />-->
      <layout type="log4net.Layout.PatternLayout,log4net">
        <ConversionPattern value="%d [%t] %-5p %c - %m%n" />
        <Header value="&#xD;&#xA;----------------------Header--------------------------&#xD;&#xA;" />
        <Footer value="&#xD;&#xA;----------------------Footer--------------------------&#xD;&#xA;" />
      </layout>
    </appender>
    <!-- Setup the root category, add the appenders and set the default level -->
    <root>
      <level value="ALL" />
      <appender-ref ref="ConsoleAppender" />
      <!--<appender-ref ref="FileAppender" />-->
      <appender-ref ref="RollingLogFileAppender" />
    </root>
  </log4net>
</configuration>

在startup的构造函数中注入log4net

        public static ILoggerRepository LogRepository { get; set; }
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
            LogRepository = LogManager.CreateRepository("NETCoreRepository");   //仓库的名字可以在配置文件中配置，也可以直接写死
            XmlConfigurator.Configure(LogRepository, new FileInfo("log4net.config"));  //读取配置文件
        }

在Controller中实例化
先获取一个ILog对象实例

//type 是指你当前使用log的对象的类，例如需要在HomeController中使用，参数就为typeof(HomeController)
private readonly ILog _log = LogManager.GetLogger(Startup.LogRepository.Name, Type type);

在Action中使用

_log.Error(e.ToString());