第一步：NuGet安装Log4net，配置Web.config：
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" /> </configSections>第二步：新建Log4Net.config的配置文件，并在其中添加下面的配置信息：
写入数据库的配置：
写入文件的配置：
第三步：在Global.asax文件中的Application_Start事件中添加如下代码：
protected void Application_Start()
{//......
//日志 log4net.Config.XmlConfigurator.ConfigureAndWatch(new FileInfo(Server.MapPath("~/log4net.config"))); }第四步：调用log4net写日志
public log4net.Ext.IExtLog log = log4net.Ext.ExtLogManager.GetLogger("dblog");
log.Warn(Utils.GetIP(), item.ACCOUNT, Request.Url.ToString(), "Login", "系统登录，登录结果：" + json.Msg);
log.Info(Utils.GetIP(), item.ACCOUNT, Request.Url.ToString(), "Login", "系统登录，登录结果：" + json.Msg);
log.Error(Utils.GetIP(), item.ACCOUNT, Request.Url.ToString(), "Login", "系统登录，登录结果：" + json.Msg);
封装好的辅助类：
ExtLogImpl
using System;using System.Collections.Generic;using System.Linq;using System.Text;using log4net.Core;namespace log4net.Ext{ public class ExtLogImpl : LogImpl, IExtLog { /// /// The fully qualified name of this declaring type not the type of any subclass. /// private readonly static Type ThisDeclaringType = typeof(ExtLogImpl); public ExtLogImpl(ILogger logger) : base(logger) { } #region IExtLog 成员 public void Info(string clientIP, string clientUser, string requestUri, string action, object message) { Info(clientIP, clientUser, requestUri, action, message, null); } public void Info(string clientIP, string clientUser, string requestUri, string action, object message, Exception t) { if (this.IsInfoEnabled) { LoggingEvent loggingEvent = new LoggingEvent(ThisDeclaringType, Logger.Repository, Logger.Name, Level.Info, message, t); loggingEvent.Properties["ClientIP"] = clientIP; loggingEvent.Properties["ClientUser"] = clientUser; loggingEvent.Properties["RequestUrl"] = requestUri; loggingEvent.Properties["Action"] = action; Logger.Log(loggingEvent); } } public void Warn(string clientIP, string clientUser, string requestUri, string action, object message) { Warn(clientIP, clientUser, requestUri, action, message, null); } public void Warn(string clientIP, string clientUser, string requestUri, string action, object message, Exception t) { if (this.IsWarnEnabled) { LoggingEvent loggingEvent = new LoggingEvent(ThisDeclaringType, Logger.Repository, Logger.Name, Level.Warn, message, t); loggingEvent.Properties["ClientIP"] = clientIP; loggingEvent.Properties["ClientUser"] = clientUser; loggingEvent.Properties["RequestUrl"] = requestUri; loggingEvent.Properties["Action"] = action; Logger.Log(loggingEvent); } } public void Error(string clientIP, string clientUser, string requestUri, string action, object message) { Error(clientIP, clientUser, requestUri, action, message, null); } public void Error(string clientIP, string clientUser, string requestUri, string action, object message, Exception t) { if (this.IsErrorEnabled) { LoggingEvent loggingEvent = new LoggingEvent(ThisDeclaringType, Logger.Repository, Logger.Name, Level.Error, message, t); loggingEvent.Properties["ClientIP"] = clientIP; loggingEvent.Properties["ClientUser"] = clientUser; loggingEvent.Properties["RequestUrl"] = requestUri; loggingEvent.Properties["Action"] = action; Logger.Log(loggingEvent); } } public void Fatal(string clientIP, string clientUser, string requestUri, string action, object message) { Fatal(clientIP, clientUser, requestUri, action, message, null); } public void Fatal(string clientIP, string clientUser, string requestUri, string action, object message, Exception t) { if (this.IsFatalEnabled) { LoggingEvent loggingEvent = new LoggingEvent(ThisDeclaringType, Logger.Repository, Logger.Name, Level.Fatal, message, t); loggingEvent.Properties["ClientIP"] = clientIP; loggingEvent.Properties["ClientUser"] = clientUser; loggingEvent.Properties["RequestUrl"] = requestUri; loggingEvent.Properties["Action"] = action; Logger.Log(loggingEvent); } } #endregion }} ExtLogManager
using log4net.Core;using System;using System.Collections.Generic;using System.Linq;using System.Reflection;using System.Text;namespace log4net.Ext{ public class ExtLogManager { #region Static Member Variables /// /// The wrapper map to use to hold the private static readonly WrapperMap s_wrapperMap = new WrapperMap(new WrapperCreationHandler(WrapperCreationHandler)); #endregion #region Constructor /// /// Private constructor to prevent object creation /// private ExtLogManager() { } #endregion #region Type Specific Manager Methods /// /// Returns the named logger if it exists /// /// /// If the named logger exists (in the default hierarchy) then it /// returns a reference to the logger, otherwise it returns /// null . /// /// The fully qualified logger name to look for /// The logger found, or null public static IExtLog Exists(string name) { return Exists(Assembly.GetCallingAssembly(), name); } /// /// Returns the named logger if it exists /// /// /// If the named logger exists (in the specified domain) then it /// returns a reference to the logger, otherwise it returns /// null . /// /// the domain to lookup in /// The fully qualified logger name to look for /// The logger found, or null public static IExtLog Exists(string domain, string name) { return WrapLogger(LoggerManager.Exists(domain, name)); } /// /// Returns the named logger if it exists /// /// /// If the named logger exists (in the specified assembly's domain) then it /// returns a reference to the logger, otherwise it returns /// null . /// /// the assembly to use to lookup the domain /// The fully qualified logger name to look for /// The logger found, or null public static IExtLog Exists(Assembly assembly, string name) { return WrapLogger(LoggerManager.Exists(assembly, name)); } /// /// Returns all the currently defined loggers in the default domain. /// /// /// The root logger is not included in the returned array. /// /// All the defined loggers public static IExtLog[] GetCurrentLoggers() { return GetCurrentLoggers(Assembly.GetCallingAssembly()); } /// /// Returns all the currently defined loggers in the specified domain. /// /// the domain to lookup in /// /// The root logger is not included in the returned array. /// /// All the defined loggers public static IExtLog[] GetCurrentLoggers(string domain) { return WrapLoggers(LoggerManager.GetCurrentLoggers(domain)); } /// /// Returns all the currently defined loggers in the specified assembly's domain. /// /// the assembly to use to lookup the domain /// /// The root logger is not included in the returned array. /// /// All the defined loggers public static IExtLog[] GetCurrentLoggers(Assembly assembly) { return WrapLoggers(LoggerManager.GetCurrentLoggers(assembly)); } /// /// Retrieve or create a named logger. /// /// /// Retrieve a logger named as the /// /// By default, loggers do not have a set level but inherit /// it from the hierarchy. This is one of the central features of /// log4net. /// /// The name of the logger to retrieve. /// the logger with the name specified public static IExtLog GetLogger(string name) { return GetLogger(Assembly.GetCallingAssembly(), name); } /// /// Retrieve or create a named logger. /// /// /// Retrieve a logger named as the /// /// By default, loggers do not have a set level but inherit /// it from the hierarchy. This is one of the central features of /// log4net. /// /// the domain to lookup in /// The name of the logger to retrieve. /// the logger with the name specified public static IExtLog GetLogger(string domain, string name) { return WrapLogger(LoggerManager.GetLogger(domain, name)); } /// /// Retrieve or create a named logger. /// /// /// Retrieve a logger named as the /// /// By default, loggers do not have a set level but inherit /// it from the hierarchy. This is one of the central features of /// log4net. /// /// the assembly to use to lookup the domain /// The name of the logger to retrieve. /// the logger with the name specified public static IExtLog GetLogger(Assembly assembly, string name) { return WrapLogger(LoggerManager.GetLogger(assembly, name)); } /// /// Shorthand for /// /// Get the logger for the fully qualified name of the type specified. /// /// The full name of the logger with the name specified public static IExtLog GetLogger(Type type) { return GetLogger(Assembly.GetCallingAssembly(), type.FullName); } /// /// Shorthand for /// /// Get the logger for the fully qualified name of the type specified. /// /// the domain to lookup in /// The full name of the logger with the name specified public static IExtLog GetLogger(string domain, Type type) { return WrapLogger(LoggerManager.GetLogger(domain, type)); } /// /// Shorthand for /// /// Get the logger for the fully qualified name of the type specified. /// /// the assembly to use to lookup the domain /// The full name of the logger with the name specified public static IExtLog GetLogger(Assembly assembly, Type type) { return WrapLogger(LoggerManager.GetLogger(assembly, type)); } #endregion #region Extension Handlers /// /// Lookup the wrapper object for the logger specified /// /// the logger to get the wrapper for /// the wrapper for the logger specified private static IExtLog WrapLogger(ILogger logger) { return (IExtLog)s_wrapperMap.GetWrapper(logger); } /// /// Lookup the wrapper objects for the loggers specified /// /// the loggers to get the wrappers for /// Lookup the wrapper objects for the loggers specified private static IExtLog[] WrapLoggers(ILogger[] loggers) { IExtLog[] results = new IExtLog[loggers.Length]; for (int i = 0; i < loggers.Length; i++) { results[i] = WrapLogger(loggers[i]); } return results; } /// /// Method to create the /// The logger to wrap /// The wrapper for the logger specified private static ILoggerWrapper WrapperCreationHandler(ILogger logger) { return new ExtLogImpl(logger); } #endregion }} IExtLog
using System;using System.Collections.Generic;using System.Linq;using System.Text;using log4net;namespace log4net.Ext{ public interface IExtLog : ILog { void Info(string clientIP, string clientUser, string requestUri, string action, object message); void Info(string clientIP, string clientUser, string requestUri, string action, object message, Exception t); void Warn(string clientIP, string clientUser, string requestUri, string action, object message); void Warn(string clientIP, string clientUser, string requestUri, string action, object message, Exception t); void Error(string clientIP, string clientUser, string requestUri, string action, object message); void Error(string clientIP, string clientUser, string requestUri, string action, object message, Exception t); void Fatal(string clientIP, string clientUser, string requestUri, string action, object message); void Fatal(string clientIP, string clientUser, string requestUri, string action, object message, Exception t); }} 参考：
http://www.cnblogs.com/huanghai223/archive/2012/02/21/2361529.html
http://www.cnblogs.com/jiajinyi/p/5884930.html