编写操作日志类的方法

using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.IO;namespace Discuz.WebService{    public class LogWrite    {        private string filePath = null;        public LogWrite()        {            try            {                string Dir = HttpContext.Current.Server.MapPath("~/Log/");                if (!Directory.Exists(Dir))                {                    Directory.CreateDirectory(Dir);                }                filePath = Dir + DateTime.Now.ToString("yyyy-MM-dd") + ".log";            }            catch (Exception) { }        }        /// <summary>        /// 写入错误信息        /// </summary>        /// <param name="ex"></param>        public void WriteLog(Exception ex, string IP)        {            using (StreamWriter sw = new StreamWriter(filePath, true, System.Text.Encoding.UTF8))            {                sw.WriteLine(string.Format("时间:{0} 错误原因:{1}", DateTime.Now.ToString(), ex.Message));                sw.WriteLine(string.Format("用户IP:{0}", IP));                sw.WriteLine("错误信息:");                sw.WriteLine(ex.StackTrace);                sw.WriteLine("-----------------------------------------------------------------------------------------------");                sw.WriteLine("");                sw.Flush();                sw.Close();            }        }        /// <summary>        /// 写入错误信息        /// </summary>        /// <param name="ex"></param>        public void WriteLog(string msg, string IP)        {            using (StreamWriter sw = new StreamWriter(filePath, true, System.Text.Encoding.UTF8))            {                sw.WriteLine(string.Format("时间:{0} 错误原因:{1}", DateTime.Now.ToString(), msg));                sw.WriteLine(string.Format("用户IP:{0}", IP));                sw.WriteLine("-----------------------------------------------------------------------------------------------");                sw.WriteLine("");                sw.Flush();                sw.Close();            }        }    }}