c#操作文件实现日志功能

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace LogDemo
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 操作文件实现日志
        /// </summary>
        /// <param name="msg">日志内容</param>
        /// <param name="lonPath">存放日志的目录，如果想默认存在项目的Debag下，请输入Null</param>
        private void logger(String msg,string lonPath)
        {
            string LogPath = null;
            if (lonPath != null)
            {
                LogPath = lonPath;
            }
            else
            {
                LogPath =Application.StartupPath;
            }
            string filePath = LogPath + "\\" + DateTime.Now.Year.ToString()+"年" + DateTime.Now.Month.ToString()+"月";
            string fileName = DateTime.Now.Day.ToString() + "日" + ".Log";
            string filePathAll = filePath + "\\" + fileName;
            if (!System.IO.Directory.Exists(filePath))
            {
                System.IO.Directory.CreateDirectory(filePath);
            }
            FileStream filestream = new FileStream(filePathAll, FileMode.OpenOrCreate, FileAccess.Write, FileShare.None);
            StreamWriter writer = new StreamWriter(filestream, System.Text.Encoding.Default);
            writer.BaseStream.Seek(0, SeekOrigin.End);
            writer.WriteLine("{0} {1}", DateTime.Now.TimeOfDay , msg);
            writer.Flush();
            writer.Close();
            filestream.Close();
        }

        //测试方法
        private void button1_Click(object sender, EventArgs e)
        {
            byte str=0 ;

            try
            {
                if (true)
                {
                    str = (byte)Convert.ToSByte(600);
                }
                else
                {
                    str = (byte)Convert.ToSByte(500);
                }
            }
            catch(Exception ex)
            {
                logger(ex.Message,null);
            }
        }
    }
}