I am trying to copy a text file in an other text file line by line. It seems that there is a buffer of 1024 character. If there is less than 1024 character in my file, my function will not copie in the other file.

Also if there is more than 1024 character but less a factor of 1024, these exceeding characters will not be copied.

Ex:

2048 character in initial file - 2048 copied

988 character in initial file - 0 copied

1256 character in initial file - 1024 copied

Thks!

 private void button3_Click(object sender, EventArgs e)
    {
        // écrire code pour reprendre le nom  du fichier sélectionné et 
        //ajouter un suffix "_poly.txt"
        string ma_ligne;
        const int RMV_CARCT = 9;

        //délcaration des fichier
        FileStream apt_file = new FileStream(textBox1.Text, FileMode.Open, FileAccess.Read);
        textBox1.Text = textBox1.Text.Replace(".txt", "_mod.txt");
        FileStream mdi_file = new FileStream(textBox1.Text, FileMode.OpenOrCreate,FileAccess.ReadWrite);

        //lecture/ecriture des fichiers en question
      StreamReader apt = new StreamReader(apt_file);
      StreamWriter mdi_line = new StreamWriter(mdi_file, System.Text.Encoding.UTF8, 16);



      while (apt.Peek() >= 0)
      {
          ma_ligne = apt.ReadLine();
          //if (ma_ligne.StartsWith("GOTO"))
          //{
          //   ma_ligne = ma_ligne.Remove(0, RMV_CARCT);
          //   ma_ligne = ma_ligne.Replace(" ","");
          //   ma_ligne = ma_ligne.Replace(",", " ");
          mdi_line.WriteLine(ma_ligne);
          //}
      }
      apt_file.Close();
      mdi_file.Close();
    }