log4net的简单使用记录一下，防止下次忘记

　　1.在程序的assembly.cs下添加: [assembly: log4net.Config.XmlConfigurator(Watch = true)]  (忘记这一步，弄了半天，上次好像也是这样，不常用还是记录下好)

2.程序引用log4net,定义记录Log的实例 ： ILog _log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().GetType());

3.配置文件:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<!-- Register a section handler for the log4net section -->
<configSections>
<section name="log4net" type="System.Configuration.IgnoreSectionHandler" />
</configSections>
<!-- This section contains the log4net configuration settings -->
<log4net>
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="log\\" />
<!-- Example using environment variables in params -->
<!-- <file value="${TMP}\log-file.txt" /> -->
<appendToFile value="true" />
<rollingStyle value="Date" />
<datePattern value="yyyyMMdd&quot;.txt&quot;" />
<StaticLogFileName value="false"/>
<!-- An alternate output encoding can be specified -->
<!-- <encoding value="unicodeFFFE" /> -->
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger - %m%n" />
</layout>
<!-- Alternate layout using XML
<layout type="log4net.Layout.XMLLayout" /> -->
</appender>
<appender name="TraceAppender" type="log4net.Appender.TraceAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date-->%m%n" />
</layout>
</appender>
<!-- Setup the root category, add the appenders and set the default level -->
<root>

<!--记录日志的级别，ALL是记录所有的，debug,info,warn,error-->

<level value="ALL" />
<appender-ref ref="LogFileAppender" />
<!--appender-ref ref="TraceAppender" /-->
</root>
</log4net>

</configuration>