C#

public static void Copy(string sourcePath, string destPath, bool overwrite, int bufferSize, ProgressBar tmp_pb)
{
    if (!overwrite && File.Exists(destPath))
        throw new ArgumentException("File already exists.");

    if (!Directory.Exists(Path.GetDirectoryName(destPath)))
        Directory.CreateDirectory(Path.GetDirectoryName(destPath));

    ////creating non exists directories
    //string[] tmp_destSecs = .Split('\\');
    //for (int a = 1; a <= tmp_destSecs.Length; a++)
    //{
    //    if (!Directory.Exists(string.Join("\\", tmp_destSecs, 0, a)))
    //        Directory.CreateDirectory(string.Join("\\", tmp_destSecs, 0, a));
    //}


    FileStream tmp_fr = new FileStream(sourcePath, FileMode.Open);
    FileStream tmp_fw = new FileStream(destPath, FileMode.Create);

    long fileSize = new FileInfo(sourcePath).Length;
    if (fileSize < bufferSize)
        bufferSize = (int)fileSize;
    long numOfLoops = (fileSize / bufferSize);
    tmp_pb.Step = tmp_pb.Maximum / (int)numOfLoops;
    byte[] tmp_data;
    for (int a = 0; a < numOfLoops; a++)
    {
        tmp_data = new byte[bufferSize];
        tmp_fr.Read(tmp_data, 0, bufferSize);
        tmp_fw.Write(tmp_data, 0, bufferSize);
        tmp_pb.PerformStep();
        Application.DoEvents();
    }
    int leftBytes = (int)(fileSize - tmp_fr.Position);
    if (leftBytes > 0)
    {
        tmp_data = new byte[leftBytes];
        tmp_fr.Read(tmp_data, 0, leftBytes);
        tmp_fw.Write(tmp_data, 0, leftBytes);
    }
    tmp_fr.Close();
    tmp_fw.Flush();
    tmp_fw.Close();
    tmp_pb.Value = 0;
}

StreamReader sr = new StreamReader("inputfile.docx");
StreamWriter sw = new StreamWriter("outputfile.docx", false);

FileInfo fi = new FileInfo("inputfile.docx");
long total = fi.Length;

byte[] buffer = new byte[10000];
long byteCount = 0;

while(true)
{
  int bytesRead = sr.BaseStream.Read(buffer, 0, buffer.Length);//using .Length should ensure correct size
  byteCount += bytesRead;

  if(bytesRead == 0)//if end of file then break the loop
    break;

  //update progress
  sw.BaseStream.Write(buffer, 0, buffer.Length);
}

sr.Close();
sw.Close();

musefan wrote:

sw.BaseStream.Write(buffer, 0, buffer.Length);

sw.BaseStream.Write(buffer, 0, bytesRead);

StreamReader sr = new StreamReader("inputfile.docx");
StreamWriter sw = new StreamWriter("outputfile.docx", false);

FileInfo fi = new FileInfo("inputfile.docx");
long total = fi.Length;

byte[] buffer = new byte[10000];
long byteCount = 0;

while(true)
{
  int bytesRead = sr.BaseStream.Read(buffer, 0, buffer.Length);//using .Length should ensure correct size
  byteCount += bytesRead;

  if(bytesRead == 0)//if end of file then break the loop
    break;

  //update progress
  sw.BaseStream.Write(buffer, 0, bytesRead); //otherwise you would write a piece of unused buffer space
}

sr.Close();
sw.Close();

void Copier(String src, String dest) {
  using (FileStream srcfile = new FileStream(src, FileMode.Open, FileAccess.Read)) {
    using (FileStream destfile = new FileStream(dest, FileMode.CreateNew, FileAccess.Write)){
      byte[] buffer = new byte[16 * 1024];
      Int32 bytesRead;
      while((bytesRead = srcfile.Read(buffer, 0, buffer.Length)) != 0 ){
        destfile.Write(buffer, 0, bytesRead);
      }
    }
  }
}