File读文件：

var path = Path.Combine(Environment.CurrentDirectory,"App.config");
            if (!File.Exists(path))
                throw new FileNotFoundException("本地App.config文件不存在！");
            byte[] byteArray = File.ReadAllBytes(path); //读路径中的文件得到字节数组

File写文件：

var path = Path.Combine(Environment.CurrentDirectory,"App.config");
            //删除原有模板
            if (File.Exists(path))
            {
                File.Delete(path);
            }
            if (bytes != null)
                File.WriteAllBytes(localAppConfigPath,bytes);

XmlDocument读xml文件：

var doc = new XmlDocument();
            var path = Path.Combine(Environment.CurrentDirectory,"App.config");
            if (!File.Exists(path))
                throw new FileNotFoundException("本地app.config文件不存在！");
            doc.Load(path);
            byte[] bytes = Encoding.ASCII.GetBytes(doc.InnerXml);

XmlDocument写文件：

doc.RemoveAll();
            doc.InnerXml = docServer.InnerXml;
            doc.Save(path);

WebService接口
读文件接口：

[WebMethod]
        public byte[] ReadFromFile(string fileName)
        {
            try
            {
                fileName = Path.Combine("ServerFiles",fileName);
                fileName = Path.Combine(Server.MapPath("."),fileName);
                if (File.Exists(fileName))
                {
                    FileStream stream = File.Open(fileName,FileMode.Open);
                    byte[] buffer = new byte[stream.Length];
                    stream.Read(buffer,0,((int)stream.Length));
                    stream.Close();
                    return buffer;
                }
                throw new Exception("服务器上的文件不存在！");
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

写文件接口：

[WebMethod]
        public bool WriteToFile(string fileName,byte[] buffer)
        {
            try
            {
                fileName = Path.Combine("ServerFiles",fileName);
                FileStream stream = new FileStream(fileName,FileMode.Create,FileAccess.ReadWrite);
                stream.Write(buffer,buffer.Length);
                stream.Close();
                return true;
            }
            catch (Exception ex)
            {
                throw ex;
            }

        }