如何获取特定pdf表单字段的页码和位置,并在iText7中插入表格？

Question

我想在表单字段的位置插入一个表.如何获取表单字段的位置和页码？如何在该位置插入表格？

//Retrieves AcroForm from the document.
//If there is no AcroForm in the document Catalog and createIfNotExist
//flag is true then the AcroForm dictionary will be created and added to the document.
PdfAcroForm acroForm = PdfAcroForm.getAcroForm(pdfDoc, true);
//Gets the form fields as a Map.
Map<String, PdfFormField> fields = acroForm.getFormFields();
//Create Table
Table table = new Table(new float[]{1,1});
table.setHorizontalAlignment(HorizontalAlignment.CENTER);
table.setWidthPercent(95);  
Cell cell = new Cell();
cell.add(new Paragraph("Name"));
//cell.setBorder(Border.NO_BORDER);
table.addCell(cell);
Cell cell = new Cell();
cell.add(new Paragraph("Address"));
//cell.setBorder(Border.NO_BORDER);
table.addCell(cell);
...
...
doc.add(table);
...

Answer 1

字段本身没有任何位置或页码.但是,它的小部件注释可以.

要访问它们,您可以使用field.getWidgets().然后,您可以使用annotation.getPage()和annotation.getRectangle()获取有关注释位置的信息.

要在某个特定位置布局单个元素,最好的选择之一是使用Canvas布局对象.然后可以删除注释page.removeAnnotation(annotation);.

总的来说,这可以编译成以下解决方案:

String fieldName = "Text1";
PdfFormField field = form.getField(fieldName);

for (PdfAnnotation annotation : field.getWidgets()) {
    PdfPage page = annotation.getPage();
    Rectangle rectangle = annotation.getRectangle().toRectangle();

    Table table = new Table(UnitValue.createPointArray(new float[] {-1, -1}));
    table.setHorizontalAlignment(HorizontalAlignment.CENTER);
    Cell cell = new Cell();
    cell.add(new Paragraph("Name"));
    table.addCell(cell);
    cell = new Cell();
    cell.add(new Paragraph("Address"));
    table.addCell(cell);

    Canvas canvas = new Canvas(new PdfCanvas(page), pdfDocument, rectangle);
    canvas.add(table);
    canvas.close();

    page.removeAnnotation(annotation);
}

当然,您必须全权负责创建适当大小的表格,以便它适合您想要的区域.您可以使用较小的字体大小等.