使用 itextsharp pdf 套表 barcode

1. 取得套表欄位定位
float[] fl = pdfForm.GetFieldPositions(item.Field);
pageNum = fl[0]; //頁次
llx = fl[1]; //left
lly = fl[2]; //bottom
urx = fl[3]; //right
ury = fl[4]; //top
Rectangle rect = new Rectangle(llx, lly, urx, ury);//左下角右上角
PdfContentByte cb = pdfStamper.GetOverContent((int)pageNum);
Barcode39 bc39 = new Barcode39();
bc39.Code = item.Value;
bc39.BarHeight = 18;
bc39.Extended = true;
iTextSharp.text.Image BImage = bc39.CreateImageWithBarcode(cb, null, null);
BImage.SetAbsolutePosition(llx, lly);
cb.AddImage(BImage);