上传进度基础

HttpFileCollection hfc = Request.Files;
        if (hfc.Count > 0)
        {
            FileStream fs;
            Stream _stream;
            int btLen = 10000;
            byte[] _byte = new byte[btLen];
            int len, ysc = 0;
            string _root = Server.MapPath("~");
            HttpPostedFile hpf;
            foreach (string str in hfc)
            {
                hpf = hfc[str];
                if (hpf.ContentLength > 0)
                {
                    fs = new FileStream(_root + "/" + hpf.FileName, FileMode.Create);
                    _stream = hpf.InputStream;
                    len = _stream.Read(_byte, 0, btLen);
                    while (len > 0)
                    {
                        ysc += len;
                        fs.Write(_byte, 0, len);
                        len = _stream.Read(_byte, 0, btLen);
                    }
                    _byte = null;
                    hpf = null;
                    _stream.Close();
                    _stream = null;
                    fs.Close();
                    fs = null;
                }
            }
        }
//实时获取 根据ysc和hpf.ContentLength计算上传进度