public PdfPCell RenderingCell(CellAttributes attributes)
{
if (OnSelectSymbol == null)
throw new InvalidOperationException("Please set the OnSelectSymbol formula.");
var font = FontFactory.GetFont(WingdingsFontPath, BaseFont.IDENTITY_H, true, attributes.BasicProperties.PdfFont.Size, Font.NORMAL, attributes.BasicProperties.FontColor);
var symbol = (int)OnSelectSymbol.Invoke(attributes.RowData.TableRowData);
return new PdfPCell(new Phrase(new Chunk((char)symbol, font)));
}