基础上手

.net coer

1.Nuget：log4net.AspNetCore 项目加入包

2.Program.cs 类中

 public static IHostBuilder CreateHostBuilder(string[] args) =>
                Host.CreateDefaultBuilder(args)
                .ConfigureLogging((hostingContext, builder) =>
                {
                    builder.AddLog4Net();     
                })
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder
                    .UseStartup<Startup>();
                   
                });

3.Strat.cs  类  替换原有日志框架

public void Configure(IApplicationBuilder app, IWebHostEnvironment env,ILoggerFactory loggerFactory)
    {
            loggerFactory.AddLog4Net();
            //...
    }        

4. 当前项目加入配置文件 log4net.config  

<?xml version="1.0" encoding="utf-8"?>
<log4net>
  <!-- Define some output appenders -->
  <appender name="rollingAppender" type="log4net.Appender.RollingFileAppender">
    <file value="log\log.txt" />

    <!--追加日志内容-->
    <appendToFile value="true" />

    <!--防止多线程时不能写Log,官方说线程非安全-->
    <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />

    <!--可以为:Once|Size|Date|Composite-->
    <!--Composite为Size和Date的组合-->
    <rollingStyle value="Composite" />

    <!--当备份文件时,为文件名加的后缀-->
    <datePattern value="yyyyMMdd.TXT" />

    <!--日志最大个数,都是最新的-->
    <!--rollingStyle节点为Size时,只能有value个日志-->
    <!--rollingStyle节点为Composite时,每天有value个日志-->
    <maxSizeRollBackups value="20" />

    <!--可用的单位:KB|MB|GB-->
    <maximumFileSize value="3MB" />

    <!--置为true,当前最新日志文件名永远为file节中的名字-->
    <staticLogFileName value="true" />

    <!--输出级别在INFO和ERROR之间的日志-->
    <filter type="log4net.Filter.LevelRangeFilter">
      <param name="LevelMin" value="FATAL" />
      <param name="LevelMax" value="ALL" />
    </filter>

    <layout type="log4net.Layout.PatternLayout">
      <conversionPattern value="%date [%thread] %-5level %logger - %message%newline"/>
    </layout>
  </appender>

  <!-- levels: OFF > FATAL > ERROR > WARN > INFO > DEBUG  > ALL -->
  <root>
    <priority value="ALL"/>
    <level value="ALL"/>
    <appender-ref ref="rollingAppender" />
  </root>
</log4net>

5. 全局静态使用

private static readonly ILog log = LogManager.GetLogger(typeof(Startup));

或直接构造函数依赖注入

  public TController(ILog log) 

DI容器为 Autofa 时，使用依赖注入，Autofac需配置

 public class LogginModule: Autofac.Module
    {
        private static void InjectLoggerProperties(object instance)
        {
            var instanceType = instance.GetType();

            // Get all the injectable properties to set.
            // If you wanted to ensure the properties were only UNSET properties,
            // here's where you'd do it.
            var properties = instanceType
              .GetProperties(BindingFlags.Public | BindingFlags.Instance)
              .Where(p => p.PropertyType == typeof(ILog) && p.CanWrite && p.GetIndexParameters().Length == 0);

            // Set the properties located.
            foreach (var propToSet in properties)
            {
                propToSet.SetValue(instance, LogManager.GetLogger(instanceType), null);
            }
        }

        private static void OnComponentPreparing(object sender, PreparingEventArgs e)
        {
            e.Parameters = e.Parameters.Union(
              new[]
              {
        new ResolvedParameter(
            (p, i) => p.ParameterType == typeof(ILog),
            (p, i) => LogManager.GetLogger(p.Member.DeclaringType)
        ),
              });
        }

        protected override void AttachToComponentRegistration(IComponentRegistryBuilder componentRegistryBuilder, IComponentRegistration registration)
        {
            // Handle constructor parameters.
            registration.Preparing += OnComponentPreparing;

            // Handle properties.
            registration.Activated += (sender, e) => InjectLoggerProperties(e.Instance);
        }
    }

 官网：https://logging.apache.org/log4net/index.html