string[] a;
  StreamReader srReadLine = new StreamReader(
        (System.IO.Stream)File.OpenRead("XXXXX.txt"),
         System.Text.Encoding.ASCII);
         srReadLine.BaseStream.Seek(0, SeekOrigin.Begin);
         while (srReadLine.Peek() > -1) {
            a=srReadLine.ReadLine();
         }
         srReadLine.Close();
可以读一行写一行。