读写txt文件

   public void SetUpdateTime(string strNewDate)
        {
            try
            {
                var path =Application.StartupPath + ConfigurationManager.AppSettings["UpdateFile"];
                // 判断文件是否存在，不存在则创建，否则读取值显示到窗体
                if (!File.Exists(path))
                {
                    FileStream fs1 = new FileStream(path, FileMode.Create, FileAccess.Write);//创建写入文件
                    StreamWriter sw = new StreamWriter(fs1);
                    sw.WriteLine(strNewDate);//开始写入值
                    sw.Close();
                    fs1.Close();
                }
                else
                {
                    FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Write);
                    StreamWriter sr = new StreamWriter(fs);
                    sr.WriteLine(strNewDate);//开始写入值
                    sr.Close();
                    fs.Close();
                }
            }
            catch (Exception e)
            {
                LogWrite.ErrorLog(e);
            }
        }

        public DateTime GetUpdatedTime()
        {
            var reslut = DateTime.MaxValue;
            StreamReader sr = null;
            try
            {
                var path = System.Windows.Forms.Application.StartupPath + ConfigurationManager.AppSettings["UpdateFile"];
                // 判断文件是否存在，不存在则创建，否则读取值显示到窗体
                sr = new StreamReader(path, Encoding.Default);
                String line = sr.ReadLine();
                if (line != null)
                {
                    reslut = Convert.ToDateTime(line.ToString());
                }
            }
            catch (Exception e)
            {
                LogWrite.ErrorLog(e);
            }
            sr.Close();
            return reslut;
        }