怎么为网站写日志（Log4Net）

1 添加log4net dll的引用

2 在web.config中添加如下代码

①放在<configSections>节点下面

<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>

②放在<configSections/>下面

<log4net>
    <!-- Define some output appenders -->
    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="Log.txt"/>
      <appendToFile value="true"/>
      <maxSizeRollBackups value="10"/>
      <maximumFileSize value="1024KB"/>
      <rollingStyle value="Size"/>
      <staticLogFileName value="true"/>
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger - %message%newline"/>
      </layout>
    </appender>
    <root>
      <level value="DEBUG"/>
      <appender-ref ref="RollingLogFileAppender"/>
    </root>
  </log4net>

3 在Global.asax页面中的Application_Start中 添加
log4net.Config.XmlConfigurator.Configure();

4 在需要输出日志的class中使用

 public partial class TestLog4Net : System.Web.UI.Page
    {
        private static ILog logger = LogManager.GetLogger(typeof(TestLog4Net));
        protected void Page_Load(object sender, EventArgs e)
        {
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            try
            {
                SqlConnection conn = new SqlConnection("错的的连接字符串!");
                conn.Open();
            }
            catch (Exception ex)
            {
                logger.Error("连接数据库失败", ex);
            }
        }
    }