log4net 将日志写入数据库

asp.net利用log4net写入日志到SqlServer数据库，Log4net是一个开源的错误日志记录项目，易用性强，源自log4j，品质值得信赖。 下面就我的安装部署log4net到MS sql server的经验与大家分享。

　　下载log4net的Dll文件并引入到项目中，在你的web主项目（比如MainWeb.csproj）添加对log4net.dll的引用，并在相应的Globall.cs文件中的Application_Start 事件中写入

           protected   void  Application_Start(Object sender, EventArgs e)
        { 
            log4net.Config.XmlConfigurator.Configure( new System.IO.FileInfo( "log4net.config" ));
        } 

在这个项目对应的Assembly.cs文件中添加一行

[assembly: log4net.Config.XmlConfigurator(ConfigFile =  "log4net.config" , Watch =  true )]  

添加logn4net.confgi在主项目根目录下：与web.config同路径，之所以不写入web,config文件， 是因为这样可以单独修改调试部署，也就是非侵入式安装的思想。

<?xml version="1.0"?>
<configuration>
    <configSections>
        <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
    </configSections>
    <!--Log4net Begin by Tony  2008.11.20-->
    <log4net>
        <appender name="ADONetAppender" type="log4net.Appender.ADONetAppender">
            <bufferSize value="10" />
            <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <connectionString value="DATABASE=DBErrorLogs;SERVER=myserver;UID=user;PWD=pwdpwd;Connect Timeout=15;" />
            <commandText value="INSERT INTO ErrorLog ([dtDate],[sThread],[sLevel],[sLogger],[sMessage],[sException]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />
            <parameter>
                <parameterName value="@log_date" />
                <dbType value="DateTime" />
                <layout type="log4net.Layout.RawTimeStampLayout" />
            </parameter>
            <parameter>
                <parameterName value="@thread" />
                <dbType value="String" />
                <size value="100" />
                <layout type="log4net.Layout.PatternLayout">
                    <conversionPattern value="%t" />
                </layout>
            </parameter>
            <parameter>
                <parameterName value="@log_level" />
                <dbType value="String" />
                <size value="200" />
                <layout type="log4net.Layout.PatternLayout">
                    <conversionPattern value="%p" />
                </layout>
            </parameter>
            <parameter>
                <parameterName value="@logger" />
                <dbType value="String" />
                <size value="500" />
                <layout type="log4net.Layout.PatternLayout">
                    <conversionPattern value="%logger" />
                </layout>
            </parameter>
           <parameter>
                <parameterName value="@message" />
                <dbType value="String" />
                <size value="3000" />
                <layout type="log4net.Layout.PatternLayout">
                    <conversionPattern value="%m" />
                </layout>
            </parameter>
            <parameter>
                <parameterName value="@exception" />
                <dbType value="String" />
                <size value="4000" />
                <layout type="log4net.Layout.ExceptionLayout" />
            </parameter>
        </appender>
        <!-- setup the root category, add the appenders and set the default level -->
        <root>
            <level value="WARN"/>
            <level value="INFO"/>
            <level value="DEBUG"/>
            <level value="FINE"/>
            <appender-ref ref="ADONetAppender" />
        </root>
        <!-- specify the level for some specific categories -->
        <logger name="iNotes">
            <level value="WARN"/>
            <level value="INFO"/>
            <level value="DEBUG"/>
            <level value="FINE"/>
            <appender-ref ref="ADONetAppender"/>
        </logger>
        <logger name="StellaLogger">
            <level value="ALL"/>
            <appender-ref ref="AdoNetAppender" />
        </logger>
    </log4net>
    <!--Log4net End-->
</configuration>  

基本完成了！需要注意的一个参数 bufferSize=10  表示是记录10 条到缓冲区，满10条后再写入SQL server,测试时将其改为1，生产环境建议100

CREATE TABLE [dbo].[ErrorLog](
    [nId] [bigint] IDENTITY(1,1) NOT NULL,
    [dtDate] [datetime] NOT NULL,
    [sThread] [nvarchar](100) NOT NULL,
    [sLevel] [nvarchar](200) NOT NULL,
    [sLogger] [nvarchar](500) NOT NULL,
    [sMessage] [nvarchar](3000) NOT NULL,
    [sException] [nvarchar](4000) NULL) 

调用代码

 public static class TestLog4
    {
        private static log4net.ILog myLogger = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
        public static void OnReceiveMsg()
        {
            myLogger.Debug("系统已记录错误，请联系管理员！");
        }
    }