public static Func<IList<CellData>, object> GetCalculatedFieldFormulaAttribute(this FieldInfo[] fieldsInfo, string forPropertyName) { foreach (var info in fieldsInfo) { var attr = info.GetCustomAttributes(true).OfType<CalculatedFieldFormulaAttribute>().FirstOrDefault(a => a.PropertyName == forPropertyName); if (attr == null) continue; var attributeValue = info.GetValue(null); return attributeValue as Func<IList<CellData>, object>; } return null; }