背景
最近在写一个Adapter，需要调用别的程序的DLL. Adapter使用的是C#还有.net的等方面的技术。今天在写log这块，就像尝试一下有没有“轮子”可以试试的。在网上搜罗了一番之后，决定就使用“log4net”吧。
关于log4net
简单来说，她是从log4j衍生出来的专门用于.net领域的一个写log的类库。支持 .net stardard，.net core等等。。。
下载
我们可以到 http://logging.apache.org/log4net/download_log4net.cgi 来下载，下载页面提供了很多种方式（binary or source）
使用
LZ这里是.net stardard,所以将下载完成后的压缩包解压，之后进入bin目录，找到对应的framework版本，选择引入“log4net.dll”
个人的想法是把这个记录log的组件封装成一个library，所以新建一个ClassLibrary工程，在里面引入“log4net.dll”并且进行封装。项目组成如下图：
其中：
- LogHelper 是一个关于调用Log4net.dll方法的封装类。
- LogLirary.config 该文件是一个配置文件，里面详细记录的log的输出/存储方式
LogHelper.cs
using System;using System.Collections.Generic;using System.Linq;using System.Text;[assembly: log4net.Config.XmlConfigurator(ConfigFile = "LogLibrary.config", ConfigFileExtension = ".config", Watch = true)]namespace LogLibary{ ???public enum LogLevel ???{ ???????Debug, ???????Info, ???????Warning, ???????Error ???} ???public class LogHelper ???{ ???????public static void WriteLog(Type t, LogLevel logLevel, string msg) ???????{ ???????????log4net.ILog log = log4net.LogManager.GetLogger(t); ???????????switch (logLevel) ????????????{ ???????????????case LogLevel.Debug: ???????????????????log.Debug(msg); ???????????????????break; ???????????????case LogLevel.Info: ???????????????????log.Info(msg); ???????????????????break; ???????????????case LogLevel.Warning: ???????????????????log.Warn(msg); ???????????????????break; ???????????????case LogLevel.Error: ???????????????????log.Error(msg); ???????????????????break; ???????????????default: ???????????????????log.Debug(msg); ???????????????????break; ???????????} ???????} ???????public static void WriteLogWithException(Type t, LogLevel logLevel, string msg, Exception ex) ???????{ ???????????log4net.ILog log = log4net.LogManager.GetLogger(t); ???????????switch (logLevel) ???????????{ ???????????????case LogLevel.Debug: ???????????????????log.Debug(msg, ex); ???????????????????break; ???????????????case LogLevel.Info: ???????????????????log.Info(msg, ex); ???????????????????break; ???????????????case LogLevel.Warning: ???????????????????log.Warn(msg, ex); ???????????????????break; ???????????????case LogLevel.Error: ???????????????????log.Error(msg, ex); ???????????????????break; ???????????????default: ???????????????????log.Debug(msg, ex); ???????????????????break; ???????????} ???????} ?????????????}}标红的语句非常重要，它表明我们log输出依赖于configuration
LogLibrary.config
<?xml version="1.0" encoding="utf-8" ?><configuration> ?<configSections> ???<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/> ?</configSections> ?<log4net> ???<!--定义输出到文件中--> ???<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender"> ?????<!--定义文件存放位置--> ?????<file value="Log\\"/> ?????<appendToFile value="true"/> ?????<rollingStyle value="Date"/> ?????<datePattern value="yyyy\\yyyyMM\\yyyyMMdd‘.txt‘"/> ?????<staticLogFileName value="false"/> ?????<param name="MaxSizeRollBackups" value="100"/> ?????<layout type="log4net.Layout.PatternLayout"> ???????<!--每条日志末尾的文字说明--> ???????<!--输出格式--> ???????<!--样例：2008-03-26 13:42:32,111 [10] INFO ?Log4NetDemo.MainClass [(null)] - info--> ???????<conversionPattern value="%newline %n记录时间：%date %n线程ID:[%thread] %n日志级别： ?%-5level %n出错类：%logger property: [%property{NDC}] - %n错误描述：%message%newline %n"/> ?????</layout> ???</appender> ???<!--定义输出到控制台命令行中--> ???<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender"> ?????<layout type="log4net.Layout.PatternLayout"> ???????<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" /> ?????</layout> ???</appender> ???<root> ?????<level value="ALL" /> ?????<!--文件形式记录日志--> ?????<appender-ref ref="RollingLogFileAppender" /> ?????<!--控制台控制显示日志--> ?????<appender-ref ref="ConsoleAppender" /> ???</root> ?</log4net></configuration>最后，写一个简单的测试类
using System;using System.Collections.Generic;using System.Linq;using System.Text;using RabbitMQ.Client;using LogLibary;namespace Producer{ ???class Program ???{ ???????static void Main(string[] args) ???????{ ???????????for (int i = 0; i < 1000; i++) // tested code here ???????????{ ??????????? string message = String.Format("Hello there! number is: {0}", i.ToString()); ?????????????????????????????LogHelper.WriteLog(typeof(Program), LogLevel.Debug, string.Format(" set {0}", message)); ???????????} ??????????????????????????????LogHelper.WriteLog(typeof(Program), LogLevel.Info, "1000 tasks sent out!!"); ?????????????????????Console.ReadKey(); ???????} ???}}参考文献：
http://logging.apache.org/log4net/release/config-examples.html
http://www.cnblogs.com/wangsaiming/archive/2013/01/11/2856253.html
OK. 啰啰嗦嗦写了一堆，感谢大家的收看，预祝各位双11 “买买买！！”
log4donet 的 一篇简单使用实例
原文地址：http://www.cnblogs.com/atuotuo/p/7787605.html