c#上传大文件方法

客户端代码：

 /// <summary>

        /// 将本地文件上传到指定的服务器(HttpWebRequest方法)

        /// </summary>

        /// <param name="address">文件上传到的服务器</param>

        /// <param name="fileNamePath">要上传的本地文件（全路径）</param>

        /// <param name="saveName">文件上传后的名称</param>

        /// <returns>服务器反馈信息</returns>

        private string Upload_Request(string address, string fileNamePath, string saveName)
        {

            // 要上传的文件

            FileStream fs = new FileStream(fileNamePath, FileMode.Open, FileAccess.Read);

            BinaryReader r = new BinaryReader(fs);

            //时间戳

            string strBoundary = "----------" + DateTime.Now.Ticks.ToString("x");

            byte[] boundaryBytes = Encoding.ASCII.GetBytes("\r\n--" + strBoundary + "\r\n");

            //请求头部信息

            StringBuilder sb = new StringBuilder();

            sb.Append("--");

            sb.Append(strBoundary);

            sb.Append("\r\n");

            sb.Append("Content-Disposition: form-data; name=\"");

            sb.Append("file");

            sb.Append("\"; filename=\"");

            sb.Append(saveName);

            sb.Append("\"");

            sb.Append("\r\n");

            sb.Append("Content-Type: ");

            sb.Append("application/octet-stream");

            sb.Append("\r\n");

            sb.Append("\r\n");

            string strPostHeader = sb.ToString();

            byte[] postHeaderBytes = Encoding.UTF8.GetBytes(strPostHeader);

            // 根据uri创建HttpWebRequest对象

            HttpWebRequest httpReq = (HttpWebRequest)WebRequest.Create(new Uri(address));

            httpReq.Method = "POST";

            //对发送的数据不使用缓存【重要、关键】

            httpReq.AllowWriteStreamBuffering = false;

            //设置获得响应的超时时间（300秒）

            //httpReq.Timeout = 300000;

            httpReq.ContentType = "multipart/form-data; boundary=" + strBoundary;

            long length = fs.Length + postHeaderBytes.Length + boundaryBytes.Length;

            long fileLength = fs.Length;

            httpReq.ContentLength = length;

            try
            {
                //每次上传4k

                int bufferLength = 4096;

                byte[] buffer = new byte[bufferLength];

                //已上传的字节数

                long offset = 0;

                //开始上传时间

                DateTime startTime = DateTime.Now;

                int size = r.Read(buffer, 0, bufferLength);

                Stream postStream = httpReq.GetRequestStream();

                //发送请求头部消息

                postStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);

                while (size > 0)
                {

                    postStream.Write(buffer, 0, size);

                    offset += size;

                    TimeSpan span = DateTime.Now - startTime;
                    //1024*1024=1048576
                    size = r.Read(buffer, 0, bufferLength);

                }

                //添加尾部的时间戳

                postStream.Write(boundaryBytes, 0, boundaryBytes.Length);

                postStream.Close();

                //获取服务器端的响应

                WebResponse webRespon = httpReq.GetResponse();

                Stream s = webRespon.GetResponseStream();

                StreamReader sr = new StreamReader(s);

                //读取服务器端返回的消息

                string serverMsg = sr.ReadLine();
                s.Close();

                sr.Close();

            }

            catch (Exception ex)
            {

            }

            finally
            {

                fs.Close();

                r.Close();

            }

            return "";

        }

服务端：

  HttpPostedFileBase file = Request.Files[0];
            file.SaveAs(Server.MapPath("~/file/k.iso"));

客户端调用：

Upload_Request("http://localhost:7115/test/index", "d:\\t.rar", "kk");