StreamWriter and StreamReader

    /// <summary>
        /// 内容写入到文本文件
        /// </summary>
        /// <param name="fileName">文件名称</param>
        /// <param name="content">内容</param>
        /// <returns>返回错误信息或时1代表写入成功</returns>
        public string writeFile(string fileName,string content)
        {
            try
            {
                string pathName = Server.MapPath(fileName);
                //这个不存在会自动创建 存在就直接覆盖了  当false为true时 就是追加了
                using (StreamWriter sw = new StreamWriter(pathName, false, Encoding.Default))
                {
                    sw.Write(content);
                    sw.Flush();
                    sw.Close();
                }
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
            return "1";
        }


        /// <summary>
        /// 读取文本文件内容
        /// </summary>
        /// <param name="fileName">文件名称</param>
        /// <returns>返回内容或o(测试的时候可以返回ex.Message)</returns>
        [AjaxPro.AjaxMethod]
        public string readFile(string fileName)
        {
            string result = "";
            try
            {
                string pathName = Server.MapPath(fileName);
                using (StreamReader sr = new StreamReader(pathName, Encoding.Default))
                {
                    result=sr.ReadToEnd();
                    sr.Close();
                }
            }
            catch (Exception ex)
            {
                return "0";//ex.Message;
            }
            return result;
        }