title: csv file encoding for cyrillic characters
body: <p>I use next code to generate .csv file from my logs table.</p>
  
  <pre><code>public ActionResult Index()
  {
  var records = loggingService.GetLogRecords(model.Since, model.For);
  
  var mainSb = new StringBuilder();
  mainSb.Append("Date,User name\n");
  
  foreach (var logRecord in records)
  {
      mainSb.Append(logRecord.Time.ToString("dd/MM/yyyy hh:mm:ss")).Append(",");
      mainSb.Append("\"").Append(logRecord.UserName ?? "").Append("\"").Append(",");
  }
  return File(Encoding.Unicode.GetBytes(mainSb.ToString()), "text/csv", string.Format("logs.csv"));
  }
  </code></pre>
  
  <p>Usernames contains cyrillic chars, and when I open my .csv file - cyrillic chars is bad displayed. I tried to use UTF8 and UTF32 encodings too. Whan encoding should I use or what changes should I do?</p>