Log4Net使用方式 (Windows + ASP.NET) @ 動不動就想吃喝玩樂

Windows 環境搭配 ASP.NET時，使用Log4Net的方式如下:

下載Log4net

1. 放置Log4Net元件(log4net.dll)至VS.NET /bin/ 目錄 (要留意.NET版本)
2. 在VS.NET專案內引用log4net.dll元件
3. 修改「log4net設定檔」，放置在虛擬應用程式的根目錄(http://xxx/AP/log4net.config)

<?xml version="1.0"?>
  <log4net>
    <!-- Setup the root category, add the appenders and set the default level -->
    <root>
      <level value="DEBUG" />
      <appender-ref ref="stdout" />
    </root>

    <logger name="com.xxx.db.DBAccess" additivity="false">
      <level value="INFO" />
      <appender-ref ref="DBAccess_Info" />
    </logger>

    <logger name="com.xxx.APException" additivity="false">
      <level value="INFO" />
      <appender-ref ref="APException_Info" />
    </logger>

    <!-- Define some output appenders -->
    <appender name="stdout" type="log4net.Appender.ConsoleAppender">
      <layout type="log4net.Layout.PatternLayout">
        <param name="ConversionPattern" value="%d [%t] %-5p %c [%x] - %m%n" />
      </layout>
    </appender>

    <!-- FileAppender appends to a log and it is manually managed or size  %d %logger %m%n  -->
    <appender name="DBAccess_Info" type="log4net.Appender.RollingFileAppender">
      <file value="c:\log\Certificate.log" />
      <appendToFile value="true" />
      <rollingStyle value="Date" />
      <datePattern value="'.'yyyy-MM-dd" />
      <layout type="log4net.Layout.PatternLayout">
        <param name="ConversionPattern" value="%d %m%n" />
      </layout>
    </appender>

    <appender name="APException_Info" type="log4net.Appender.RollingFileAppender">
      <file value="c:\log\QRStringToTraceCode.log" />
      <appendToFile value="true" />
      <rollingStyle value="Date" />
      <datePattern value="'.'yyyy-MM-dd" />
      <layout type="log4net.Layout.PatternLayout">
        <param name="ConversionPattern" value="%d %m%n" />
      </layout>
    </appender>
  </log4net>

4. 修改global.asa.cs, 當虛擬應用程式啟動時, 載入「log4net設定檔」

protected void Application_Start(Object sender, EventArgs e)
{
  log4net.Config.XmlConfigurator.ConfigureAndWatch
          (new System.IO.FileInfo(Server.MapPath("~/log4net.config")));
}

5. 程式內進行Log的寫法
5.1 引用log4net namespace

using log4net;
using log4net.Config;

5.2 宣告class層級的ILog靜態唯讀變數

private static readonly ILog logger = 
     LogManager.GetLogger("com.xxx.db.DBAccess");

5.3 使用ILog.Info("欲紀錄的字串")執行紀錄

logger.Info("紀錄字串\t紀錄字串");

參考範例：紀錄SQL Statement的執行時間與執行敘述

using System;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient;
using log4net;
using log4net.Config;

namespace com.xxx.db
{
  public class DBAccess
  {

    private static readonly ILog logger = 
            LogManager.GetLogger("com.acer.db.DBAccess");

    public DBAccess()
    {
    }

    public static int executeSelectQuery
           (string SqlStatement, DbConnection Connection, DataTable dt)
    {
      if (SqlStatement.Trim() == "")
        return -1;

      int returnRows = -1;
      try
      {
        DateTime t1 = DateTime.Now;
			  
        DbDataAdapter adapter = getAdapter(SqlStatement, Connection);
        returnRows = adapter.Fill(dt);

        TimeSpan t = DateTime.Now.Subtract(t1);

        logger.Info("\t" + t.TotalMilliseconds + " \"" + SqlStatement + "\"");

      }
      catch (Exception e)
      {
        throw e;
      }

      return returnRows;
    } 
  }
}