title: Concurrent downloading and uploading brings length error (.Net to FTP).
body: <p>I have a ftp server act as public file repository. A-app can upload file to the server and B-app can download file from the server. If B-app try to download the file which one be uploading by A-app ,file length would be incorrect.
  I wanna lock the file which be uploading to block downloading apps before uploading completed. Anyone can help me?</p>
  
  <p>I'm developing on .NetFramework.</p>