将复杂的字符串解析为DateTime

有人能告诉我如何将以下格式转换为正确的DateTime对象?

 11:50:46 AM on Wednesday, October 19, 2011 

  string s = "11:50:46 AM on Wednesday, October 19, 2011"; DateTime dateTime = DateTime.ParseExact(s, "hh:mm:ss tt on dddd, MMMM dd, yyyy", CultureInfo.InvariantCulture);