JsonKey小写

System.Text.RegularExpressions.MatchCollection ms = System.Text.RegularExpressions.Regex.Matches(ecarvoText, "\"[a-zA-Z0-9]+\"\s*:");
                    foreach (System.Text.RegularExpressions.Match item in ms)
                    {
                        ecarvoText = ecarvoText.Replace(item.Value, item.Value.ToLower());
                    }