c# 文件追加数据

//这是发送数据
FileStream fs = new FileStream(LocalFilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
            BinaryReader b = new BinaryReader(fs);
            byte[] buffer = new byte[65536];
            int data;
            while ((data =b.Read(buffer, 0, 65536))!=0) 
            {
                nft.SendFileBytes(buffer,data,RemoteSavePath);
            }
            fs.Read(buffer, 0, buffer.Length);
            fs.Close();
///这是接收数据 
FileStream fs = new FileStream(savePath, FileMode.OpenOrCreate, FileAccess.Write, FileShare.Write);
      BinaryWriter binarywrite = new BinaryWriter(fs);
                binarywrite.Seek((int)fs.Length + 1, SeekOrigin.Begin);
                byte[] b = new byte[65536];
                       //这个是接受文件流
                
                    binarywrite.Write(b, 0, data);
                                     //将接收的流用写成
                
                binarywrite.Close();
                fs.Close();
为啥接收的比发送的多个字节呢？