如何使用PDFBox将图标导入PDF中的按钮字段

Question

我正在寻找一种方法将PDF文件中的按钮字段的正常外观设置为图像文件，但我没有找到有关此过程的任何信息。

我能找到的最接近的是相反的，即如何从按钮字段提取一个图标到一个独立的图像文件，在这里:我如何使用Apache PDFBox从PDF中的按钮图标提取图像?

我更愿意使用PDFBox来完成这项任务。

Answer 1

您可以像这样使用PDFBox创建一个具有图像外观的按钮:

try (   InputStream resource = getClass().getResourceAsStream("2x2colored.png");
        PDDocument document = new PDDocument()  )
{
    BufferedImage bufferedImage = ImageIO.read(resource);
    PDImageXObject pdImageXObject = LosslessFactory.createFromImage(document, bufferedImage);
    float width = 10 * pdImageXObject.getWidth();
    float height = 10 * pdImageXObject.getHeight();
    PDAppearanceStream pdAppearanceStream = new PDAppearanceStream(document);
    pdAppearanceStream.setResources(new PDResources());
    try (PDPageContentStream pdPageContentStream = new PDPageContentStream(document, pdAppearanceStream))
    {
        pdPageContentStream.drawImage(pdImageXObject, 0, 0, width, height);
    }
    pdAppearanceStream.setBBox(new PDRectangle(width, height));
    PDPage page = new PDPage(PDRectangle.A4);
    document.addPage(page);
    PDAcroForm acroForm = new PDAcroForm(document);
    document.getDocumentCatalog().setAcroForm(acroForm);
    PDPushButton pdPushButton = new PDPushButton(acroForm);
    pdPushButton.setPartialName("ImageButton");
    List<PDAnnotationWidget> widgets = pdPushButton.getWidgets();
    for (PDAnnotationWidget pdAnnotationWidget : widgets)
    {
        pdAnnotationWidget.setRectangle(new PDRectangle(50, 750, width, height));
        pdAnnotationWidget.setPage(page);
        page.getAnnotations().add(pdAnnotationWidget);
        PDAppearanceDictionary pdAppearanceDictionary = pdAnnotationWidget.getAppearance();
        if (pdAppearanceDictionary == null)
        {
            pdAppearanceDictionary = new PDAppearanceDictionary();
            pdAnnotationWidget.setAppearance(pdAppearanceDictionary);
        }
        pdAppearanceDictionary.setNormalAppearance(pdAppearanceStream);
    }
    acroForm.getFields().add(pdPushButton);
    document.save(new File(RESULT_FOLDER, "imageButton.pdf"));
}

(CreateImageButton.java test testCreateSimpleImageButton)

由于您没有提到任何版本要求，我假设您指的是当前的PDFBox 2.0.x。