http://www.cnblogs.com/greenerycn/archive/2010/07/17/use_datetime_parseexact.html
//ShortDateFrom:yyyyMMdd格式化yyyy/MM/dd
DateTime dt = DateTime.ParseExact(noticeResult.ShortDateFrom.ToString(), "yyyyMMdd", System.Globalization.CultureInfo.CurrentCulture);
param.NoticeTime = String.Format("{0:yyyy/MM/dd}",dt);
[转]c#:用DateTime的ParseExact方法解析特殊的日期时间
原文:http://www.cnblogs.com/xiaowei-blog/p/4335706.html