问题
I want to highlight a text passage in a PDF document using iText. This passage can also span across several lines, so the highlighted region is not necessarily one rectangle.
But to the PdfAnnotation.createMarkup(...) methods I can only pass or describe one rectangle and also the PDF reference only allows for four QuadPoints to describe the region.
I would be very happy if I could achieve this with one single annotation. I know that this is possible, because I have seen documents with multi lined highlighted regions that showed up as one single entry in the annotations list.
回答1:
The QuadPoints in PDF specification is an array of 8*n elements where each set of 8 elements (x1, y1, x2, y2, x3, y3, x4, y4) defines the 4 corners of a highlighted rectangle.
The last parameter of PdfAnnotation.createMarkup is an array which accepts the values described above.
来源：https://stackoverflow.com/questions/18208636/multiline-markup-annotations-with-itext