简单代码：

/*服务器端接收写入 可以实现断点续传*/    public  string  ConnectUpload(string newfilename,string filepath,byte[] fileByte)      {　　  try{          string path = adpath + newfilename;                               FileStream fs = new FileStream(path, FileMode.Append);          BinaryWriter w = new BinaryWriter(fs);                               fs.Position = fs.Length;                               fs.Write(fileByte, 0, fileByte.Length);                               w.Close();          fs.Close();          return "1";       } 　    catch{ 　　     return "-1"; 　　       }    }    /*客户端循环添加*/    int count = 0;    int bufferSize = 256;            byte[] buffer = new byte[bufferSize];    while (count < FileUpload1.FileContent.Length)            {                    int bytes = FileUpload1.PostedFile.InputStream.Read(buffer, 0, bufferSize);                    string result = ConnectUpload(newfilename, filepath, buffer);                    if (result != "1") //报错                    {　　　　　　　　             break;        }　　　　   }