asp.net core 3.1配置log4net

1.NuGet包：

　　Microsoft.Extensions.Logging

　　Microsoft.Extensions.Logging.Log4Net.AspNetCore

添加配置文件 log4net.config

　　

<log4net>
  <appender name="Console" type="log4net.Appender.ConsoleAppender">
    <layout type="log4net.Layout.PatternLayout">
      <!-- Pattern to output the caller's file name and line number -->
      <conversionPattern value="%date %5level %logger.%method [%line] - %property{scope} %property{test} MESSAGE: %message%newline %exception" />
    </layout>
  </appender>
  <!-- 错误日志附加介质-->
  <appender name="ErrorAppender" type="log4net.Appender.RollingFileAppender">
    <!--日志文件路径-->
    <param name="File" value="Logs\Error\" />
    <!--是否是向文件中追加日志-->
    <param name="AppendToFile" value="true" />
    <!--log保留天数-->
    <param name="MaxSizeRollBackups" value="1000" />
    <!--最大文件大小-->
    <param name="MaxFileSize" value="10240" />
    <!--日志文件名是否是固定不变的-->
    <param name="StaticLogFileName" value="false" />
    <!--日志文件名格式为:2008-08-31.log-->
    <param name="DatePattern" value="yyyy-MM-dd.'log'" />
    <!--日志根据日期滚动-->
    <param name="RollingStyle" value="Date" />
    <!--信息日志布局-->
    <layout type="log4net.Layout.PatternLayout">
      <param name="ConversionPattern" value="%n＝＝＝＝＝＝＝＝＝＝%n【日志级别】：%-5level%n【记录时间】：%date %n【执行时间】：[%r]毫秒%n%message%n" />
    </layout>

    <!--FATAL > ERROR > WARN > INFO > DEBUG-->
    <filter type="log4net.Filter.LevelRangeFilter">
      <param name="LevelMin" value="ERROR" />
      <param name="LevelMax" value="FATAL" />
    </filter>
  </appender>
  <!-- 信息日志附加介质-->
  <appender name="InfoAppender" type="log4net.Appender.RollingFileAppender">
    <!--日志文件路径-->
    <param name="File" value="Logs\Info\" />
    <!--是否是向文件中追加日志-->
    <param name="AppendToFile" value="true" />
    <!--log保留天数-->
    <param name="MaxSizeRollBackups" value="100" />
    <param name="MaxFileSize" value="1" />
    <!--日志文件名是否是固定不变的-->
    <param name="StaticLogFileName" value="false" />
    <!--日志文件名格式为:2008-08-31.log-->
    <param name="DatePattern" value="yyyy-MM-dd.'log'" />
    <!--日志根据日期滚动-->
    <param name="RollingStyle" value="Date" />
    <!--信息日志布局-->
    <layout type="log4net.Layout.PatternLayout">
      <param name="ConversionPattern" value="%n＝＝＝＝＝＝＝＝＝＝%n【日志级别】：%-5p%n【记录时间】：%d [%t]%n【信息详情】：%m%n"  />
    </layout>
    <!--FATAL > ERROR > WARN > INFO > DEBUG-->
    <filter type="log4net.Filter.LevelRangeFilter">
      <param name="LevelMin" value="DEBUG" />
      <param name="LevelMax" value="WARN" />
    </filter>
  </appender>

  <appender name="TraceAppender" type="log4net.Appender.TraceAppender">
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date %5level %logger.%method [%line] - %property{scope} %property{test} MESSAGE: %message%newline %exception" />
    </layout>
  </appender>
  <appender name="ConsoleAppender" type="log4net.Appender.ManagedColoredConsoleAppender">
    <mapping>
      <level value="ERROR" />
      <foreColor value="Red" />
    </mapping>
    <mapping>
      <level value="WARN" />
      <foreColor value="Yellow" />
    </mapping>
    <mapping>
      <level value="INFO" />
      <foreColor value="White" />
    </mapping>
    <mapping>
      <level value="DEBUG" />
      <foreColor value="Green" />
    </mapping>
    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date %5level %logger.%method [%line] - %property{scope} %property{test} MESSAGE: %message%newline %exception" />
    </layout>
  </appender>
  <root>
    <level value="DEBUG" />
    <appender-ref ref="InfoAppender" />
    <appender-ref ref="TraceAppender" />
    <appender-ref ref="ConsoleAppender" />
    <appender-ref ref="ErrorAppender" />
  </root>
</log4net>

2.配置 CreateHostBuilder

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
            .ConfigureLogging((context, loggingBuilder) =>
            {
                loggingBuilder.AddFilter("System", LogLevel.Information);
                loggingBuilder.AddFilter("Microsoft", LogLevel.Information);
                var path = context.HostingEnvironment.ContentRootPath;
                loggingBuilder.AddLog4Net($"{path}/log4net.config");//配置文件
            })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                });

3.使用

    [Route("[controller]")]
    [ApiController]
    [AllowAnonymous]
    public class TestController : ControllerBase
    {
        private readonly ILogger<TestController> _logger;
        public TestController(ILogger<TestController> logger)
        {
            _logger = logger;
        }

        [HttpGet]
        public string Get()
        {
            _logger.LogInformation("LogInformation:" + DateTime.Now.ToString());
            _logger.LogWarning("LogWarning:" + DateTime.Now.ToString());
            _logger.LogError("LogError:" + DateTime.Now.ToString());
            _logger.LogDebug("LogDebug:" + DateTime.Now.ToString());
            return DateTime.Now.ToString();
        }

    }