String.Equals GID returning false?
It is gI which is not equal to GI in case of Vietnamese language. gi (GI) is syllable-initial, kind of one letter while gI are two separate letters. Other pairs are
cH != CHkH != KHnG != NGnH != NHpH != PHqU != QUtH != THtR != TR
You can try
string culture = "vi";System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo(culture);System.Threading.Thread.CurrentThread.CurrentUICulture = System.Threading.Thread.CurrentThread.CurrentCulture;var CCC = string.Equals("CategId", "CATEGID", StringComparison.InvariantCultureIgnoreCase);var CCC1 = string.Equals("CategId", "CATEGID", StringComparison.CurrentCultureIgnoreCase);In this CCC will return true but CCC1 will return false because of Culture. as per your Culture GID and gId is different.