C# Http以文件的形式上传文件

// <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>   
        /// <param name="progressBar">上传进度条</param>   
        /// <returns>成功返回1，失败返回0</returns>   
        private int Upload_Request(string address, string fileNamePath, string saveName, ProgressBar progressBar)  
        {  
            int returnValue = 0;  
  
            // 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   
            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  
            {  
                progressBar.Maximum = int.MaxValue;  
                progressBar.Minimum = 0;  
                progressBar.Value = 0;  
  
                //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;  
                    progressBar.Value = (int)(offset * (int.MaxValue / length));  
                    TimeSpan span = DateTime.Now - startTime;  
                    double second = span.TotalSeconds;  
                    lblTime.Text = "已用时：" + second.ToString("F2") + "秒";  
                    if (second > 0.001)  
                    {  
                        lblSpeed.Text = " 平均速度：" + (offset / 1024 / second).ToString("0.00") + "KB/秒";  
                    }  
                    else  
                    {  
                        lblSpeed.Text = " 正在连接…";  
                    }  
                    lblState.Text = "已上传：" + (offset * 100.0 / length).ToString("F2") + "%";  
                    lblSize.Text = (offset / 1048576.0).ToString("F2") + "M/" + (fileLength / 1048576.0).ToString("F2") + "M";  
                    Application.DoEvents();  
                    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 sReturnString = sr.ReadLine();  
                s.Close();  
                sr.Close();  
                if (sReturnString == "Success")  
                {  
                    returnValue = 1;  
                }  
                else if (sReturnString == "Error")  
                {  
                    returnValue = 0;  
                }  
  
            }  
            catch(Exception ex)  
            {  
                returnValue = 0;  
            }  
            finally  
            {  
                fs.Close();  
                r.Close();  
            }  
  
            return returnValue;  
        }