LogHelper

public class LogHelper
    {

        static string strLogCOMPath = Directory.GetCurrentDirectory() + "\\Log\\" + DateTime.Now.ToString("yyyyMMdd") + "LogJH.txt";
        static string strLogErrorPath = Directory.GetCurrentDirectory() + "\\Log\\" + DateTime.Now.ToString("yyyyMMdd") + "ErrorLog.txt";
        /// 

        /// 记录交互日志
        ///         
        /// 要记录的内容
        /// 是否要添加第一行日志title
        /// title内容
        public static void AddCOMLog(string strLogContent, bool bWriteFirstLine, string strConentTitle)
        {
            string time1;
            time1 = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff");
            if (!File.Exists(strLogCOMPath))
            {
                using (FileStream fs = new FileStream(strLogCOMPath, FileMode.Create, FileAccess.Write))
                {
                    if (bWriteFirstLine)
                    {
                        StringBuilder sb1 = new StringBuilder();
                        sb1.Append("时间").Append(",").Append(strConentTitle).Append(",").Append("\n");
                        string str = sb1.ToString();
                        byte[] buffer = Encoding.Default.GetBytes(str);
                        fs.Write(buffer, 0, buffer.Length);
                    }
                }
            }
            using (StreamWriter sw = new StreamWriter(strLogCOMPath, true, Encoding.Default))
            {
                StringBuilder sb = new StringBuilder();
                sb.Append(time1).Append(",").Append(strLogContent).Append(",");
                sw.WriteLine(sb);
            }
        }
        /// 

        /// 记录错误日志
        ///         
        /// 要记录的内容
        /// 是否要添加第一行日志title
        /// title内容
        public static void AddErrorLog(string strLogContent, bool bWriteFirstLine, string strConentTitle)
        {
            string time1;
            time1 = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff");
            if (!File.Exists(strLogErrorPath))
            {
                using (FileStream fs = new FileStream(strLogErrorPath, FileMode.Create, FileAccess.Write))
                {
                    if (bWriteFirstLine)
                    {
                        StringBuilder sb1 = new StringBuilder();
                        sb1.Append("时间").Append(",").Append(strConentTitle).Append(",").Append("\n");
                        string str = sb1.ToString();
                        byte[] buffer = Encoding.Default.GetBytes(str);
                        fs.Write(buffer, 0, buffer.Length);
                    }
                }
            }
            using (StreamWriter sw = new StreamWriter(strLogErrorPath, true, Encoding.Default))
            {
                StringBuilder sb = new StringBuilder();
                sb.Append(time1).Append(",").Append(strLogContent).Append(",");
                sw.WriteLine(sb);
            }
        }

        static readonly log4net.ILog loginfo = log4net.LogManager.GetLogger("loginfo");
        static readonly log4net.ILog logerror = log4net.LogManager.GetLogger("logerror");
        static string isAddLog = System.Configuration.ConfigurationSettings.AppSettings.Get("isAddLog");
        /// 

        /// 仅向日志中增加信息
        /// 
        /// 
        public static void WriteLog(string info)
        {
            if (isAddLog == "0")
                return;
            if (loginfo.IsInfoEnabled)
            {
                loginfo.Info(info);
            }

        }
        /// 

        /// 记录错误日志
        /// 
        /// 错误异常
        /// 异常信息
        public static void WriteLog(Exception ex, string info)
        {
            if (logerror.IsErrorEnabled)
            {
                logerror.Error(info, ex);
            }
        }
    }

<?xml version="1.0" encoding="utf-8" ?>

  
    
    "logerror">
      
      "ALL" />
      
      ref ref="ErrorAppender" />
      
    
    
    "loginfo">
      "ALL" />
      ref ref="InfoAppender" />
    
    
    "ErrorAppender" type="log4net.Appender.RollingFileAppender">
      
      "File" value="Log\\LogError\\" />
      
      "AppendToFile" value="true" />
      
      "MaxSizeRollBackups" value="100" />
      
      "MaxFileSize" value="10240" />
      
      "StaticLogFileName" value="false" />
      
      "DatePattern" value="yyyyMMdd".html"" />
      
      "RollingStyle" value="Date" />
      
      
      "log4net.Layout.PatternLayout">
        "ConversionPattern" value="<HR COLOR=red>%n异常时间：%d [%t] <BR>%n异常级别：%-5p <BR>%n异 常 类：%c [%x] <BR>%n%m <BR>%n <HR Size=1>"  />
      
    
    
    "InfoAppender" type="log4net.Appender.RollingFileAppender">
      "File" value="Log\\LogInfo\\" />
      "AppendToFile" value="true" />
      "MaxFileSize" value="10240" />
      "MaxSizeRollBackups" value="100" />
      "StaticLogFileName" value="false" />
      "DatePattern" value="yyyyMMdd".html"" />
      "RollingStyle" value="Date" />
      
      "log4net.Layout.PatternLayout">
        "ConversionPattern" value="<HR COLOR=blue>%n日志时间：%d [%t] <BR>%n日志级别：%-5p <BR>%n日 志 类：%c [%x] <BR>%n%m <BR>%n <HR Size=1>"  />
      
    
  

引用添加Log4net.DLL。

捕捉异常后，调用WriteLog方法，记录日志。

             try
            {
                  代码块
            }
           catch (Exception ex)
            {
                LogHelper.WriteLog(ex, ex.Message.ToString());
            }

使用日志时，注意2点

1.目标框架不能使用Client Profile，否则无法找到Log4net.DLL。

2.在LogHelper的Project中Assembly程序集需要添加以下代码，否则无法写日志。

[assembly: log4net.Config.XmlConfigurator(ConfigFile = "log4net.config", ConfigFileExtension = "config", Watch = true)]//让程序启动时是找到Log4net.config配置文件