对字符串到目前的转换和UTC的困惑

When I do:

当我做：

string strDate = "2013-03-03T22:58:43.0422158Z";
DateTime dt1 = DateTime.ParseExact(strDate, "o", CultureInfo.InvariantCulture);
DateTime dt2 = DateTime.ParseExact(strDate, "yyyy-MM-ddTHH:mm:ss.fffffffZ", CultureInfo.InvariantCulture);
string strDate = "2013-03-0