log4net

 log4net.Config.XmlConfigurator.Configure();//获取Log4Net配置信息(配置信息定义在Web.config文件中)

            ThreadPool.QueueUserWorkItem(o =>
            {
                while (true)
                {

                    try
                    {
                        if (ErrorHanderAttribute.qe.Count > 0)
                        {
                            Exception e = ErrorHanderAttribute.qe.Dequeue();
                            if (e != null)
                            {
                                ILog logger = LogManager.GetLogger("Log");
                                logger.Error(e);//将异常信息写到Log4Net中.
                            }
                            else
                            {
                                Thread.Sleep(100);
                            }
                        }
                        Thread.Sleep(100);
                    }
                    catch (Exception e)
                    {

                        ErrorHanderAttribute.qe.Enqueue(e);
                    }
                }
            }); 

 public class ErrorHanderAttribute : System.Web.Mvc.HandleErrorAttribute
    {
        public static Queue<Exception> qe = new Queue<Exception>();
        public override void OnException(ExceptionContext filterContext)
        {

            qe.Enqueue(filterContext.Exception);
            filterContext.HttpContext.Response.Redirect("/home/err");
            base.OnException(filterContext);
        }
    }

 <log4net>
    <!-- OFF, FATAL, ERROR, WARN, INFO, DEBUG, ALL -->
    <!-- Set root logger level to ERROR and its appenders -->
    <root>
      <level value="ALL"/>
      <appender-ref ref="SysAppender"/>
    </root>
    <!-- Print only messages of level DEBUG or above in the packages -->
    <logger name="WebLogger">
      <level value="DEBUG"/>
    </logger>
    <appender name="SysAppender" type="log4net.Appender.RollingFileAppender,log4net" >
      <param name="File" value="App_Data/" />
      <param name="AppendToFile" value="true" />
      <param name="RollingStyle" value="Date" />
      <param name="DatePattern" value="&quot;Logs_&quot;yyyyMMdd&quot;.txt&quot;" />
      <param name="StaticLogFileName" value="false" />
      <layout type="log4net.Layout.PatternLayout,log4net">
        <param name="ConversionPattern" value="%d [%t] %-5p %c - %m%n" />
        <param name="Header" value="&#13;&#10;----------------------header--------------------------&#13;&#10;" />
        <param name="Footer" value="&#13;&#10;----------------------footer--------------------------&#13;&#10;" />
      </layout>
    </appender>
    <appender name="consoleApp" type="log4net.Appender.ConsoleAppender,log4net">
      <layout type="log4net.Layout.PatternLayout,log4net">
        <param name="ConversionPattern" value="%d [%t] %-5p %c - %m%n" />
      </layout>
    </appender>
  </log4net>