public MappingEntry(Mapping mapping, ExcelWorksheet sourceWorksheet, int index) { var contentMapping = mapping as ContentMapping; var movableMapping = mapping as MovableMapping; var cellMapping = mapping as CellMapping; var formulaMapping = mapping as FormulaMapping; if (contentMapping != null) Value = contentMapping.GetValue(); else if (movableMapping != null) Value = movableMapping.GetValue(index, sourceWorksheet); else if (cellMapping != null) Value = cellMapping.GetValue(sourceWorksheet); else if (formulaMapping != null) { IsFormula = true; Value = formulaMapping.GetValue(); } else throw new InvalidOperationException("Nieznany rodzaj próbki."); Mapping = mapping; if (mapping.IsDateColumnMapping() && Value != null) Value = ExcelHelper.ToDate(Value, Mapping.Sample.Card.DateFormats.ToArray()); }