C# - Copying files and resume support

Question

Hi Does anyone have workable sample code that copy files and support resuming them if there are the source has been disconnected?

In this example I am copying videos files. If the source is disconnected ie usb was unplugged, how can I support resuming them again? I have tried some code on stackoverflow, but after resuming, the video files seem to be corrupted. Is FileStream the best solution for video transfers/resume?

Any other pointers or tips are welcome.

private void CreateNewCopyTo(FileStream source, FileStream dest) {
  int size = (source.CanSeek) ? Math.Min((int)(source.Length - source.Position), 0x2000) : 0x2000;
  byte[] buffer = new byte[size];
  int read;
  long fileLength = source.Length;
  while ((read = source.Read(buffer, 0, buffer.Length)) > 0) {
    dest.Write(buffer, 0, read);
    dest.Close();
    dest = new FileStream(dest.Name, FileMode.Append, FileAccess.Write);
  }
  dest.Close();
}

private void ResumeCopyTo(FileStream source, FileStream dest) {
  int size = (source.CanSeek) ? Math.Min((int)(source.Length - source.Position), 0x2000) : 0x2000;
  byte[] buffer = new byte[size];
  long TempPos = source.Position;
  while (true) {
    int read = source.Read(buffer, 0, buffer.Length);
    if (read <= 0)
      return;
    dest.Write(buffer, 0, read);
    dest.Close();
    dest = new FileStream(dest.Name, FileMode.Append, FileAccess.Write);
  }
}

Answer 1

Try to insert source.Seek(dest.Length, SeekOrigin.Begin); as first line in ResumeCopyTo method.