how to concatenate two byte[] values in asp.net

private byte[] CombineByteArrays(params byte[][] arrays)
{
  byte[] rv = new byte[arrays.Sum(a => a.Length)];
  int offset = 0;
  foreach (byte[] array in arrays)
  {
    System.Buffer.BlockCopy(array, 0, rv, offset, array.Length);
    offset += array.Length;
  }
  return rv;
}

byte[] header, body, footer; // All byte arrays a fill with data

byte[] content = CombineByteArrays(header, body, footer);
networkStream1.Write(content, 0, content.Length);