C# http 发送文件和接收文件的代码。

//客户端发送文件
static void Main(string[] args)
        {
            Upload_Request("http://192.168.0.4:8099/WebService/AndroidProcessRequest.aspx", @"E:\vid20140213160351.zip", @"E:\vid20140213160351.zip");
        }
        private static int Upload_Request(string address, string fileNamePath, string saveName)
        {
            int returnValue = 0;

            // 要上传的文件   
            FileStream fs = new FileStream(fileNamePath, FileMode.Open, FileAccess.ReadWrite,FileShare.ReadWrite);
            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
            {

                //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);
                    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;
        } 

　　

//接收文件 aspx挂在iis上能自动调用该类
public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "text/plain";

        context.Response.Write("id = " + context.Request.Form["id"]
            + ", name = " + context.Request.Form["name"]
            + ", count = " + context.Request.Files.Count);
        long filelegth = long.Parse(context.Request.Form["id"]);
        //WritetoLog("1");
        for (int i = 0; i < context.Request.Files.Count; i++)
        {
            try
            {
                HttpPostedFile aFile = context.Request.Files[i];
                Stream mystream = aFile.InputStream;
                //FileStream fs = (FileStream)aFile.InputStream;
                //FileStream fs = new FileStream(aFile.FileName, FileMode.Open);
                FileStream fs;
                //FileStream fs = new FileStream(aFile.FileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
                long lStartPos = 0;


                WritetoLog(aFile.FileName);
                if (aFile.ContentLength == 0 || String.IsNullOrEmpty(aFile.FileName))
                    continue;

                string displayFileName = Path.GetFileName(aFile.FileName);
                string realFileName = @"D:\" + displayFileName;		//真實路徑
               // WritetoLog(realFileName);

                if (System.IO.File.Exists(realFileName))
                {
                    WritetoLog("111111111111111");
                    fs = File.Open(realFileName, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite);
                    lStartPos = fs.Length;
                    fs.Seek(lStartPos, System.IO.SeekOrigin.Current); //移动文件流中的当前指针 
                }
                else
                {
                    WritetoLog("22222222222222");
                    fs = new System.IO.FileStream(realFileName, System.IO.FileMode.Create);
                    lStartPos = 0;
                }

                    byte[] nbytes = new byte[512];
                    int nReadSize = 0;
                    nReadSize = mystream.Read(nbytes, 0, 512);
                    while (nReadSize > 0)
                    {
                        fs.Write(nbytes, 0, nReadSize);
                        nReadSize = mystream.Read(nbytes, 0, 512);
                    }
                    if (filelegth == fs.Length)
                    { 
                        
                    }
                    fs.Close();
                    mystream.Close();
                    //Console.WriteLine("下载完成");
                
                

                //aFile.SaveAs(realFileName);

                //DownloadFile(context, realFileName, 10);
            }
            catch (Exception ex)
            {
                WritetoLog(ex.ToString());
            }
        }
    }