异常记录（写txt日志文件）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace WebBuild_CRM.Common
{
    public class ExceptionRecord
    {

        public static void RecordException(Exception ex)
        {
            FileStream fileStream = null;
            StreamWriter writer = null;
            try
            {
                string path = System.Web.HttpContext.Current.Server.MapPath("~/ExceptionLog");
                if (!Directory.Exists(path))
                    Directory.CreateDirectory(path);

                string filepath = string.Format("{0}/{1}.txt", path, DateTime.Now.ToString("yyyy-MM-dd"));
                System.IO.FileInfo fileInfo = new System.IO.FileInfo(filepath);

                if (!fileInfo.Exists)
                    fileStream = fileInfo.Create();
                else
                    fileStream = fileInfo.Open(FileMode.Append, FileAccess.Write);

                writer = new StreamWriter(fileStream);
                writer.WriteLine(DateTime.Now);
                writer.WriteLine(ex.Message);
                writer.WriteLine(ex.StackTrace);
                writer.WriteLine("");
            }
            finally
            {
                if (writer != null)
                {
                    writer.Close();
                    writer.Dispose();
                    fileStream.Close();
                    fileStream.Dispose();
                }
            }
        }

    }
}