支持表单背景图片

Workbook workbook = new Workbook();
// Fetch default worksheet
IWorksheet worksheet = workbook.getWorksheets().get(0);
worksheet.getRange("A1").setValue("GrapeCity Documents for Excel");
worksheet.getRange("A1").getFont().setSize(25);

// Load an image from a specific file in input stream
InputStream inputStream = ClassLoader.getSystemResourceAsStream("grapecity.png");
try {
    byte[] bytes = new byte[inputStream.available()];
    // Read an image from input stream
    inputStream.read(bytes, 0, bytes.length);

    // Add background image of the worksheet
    worksheet.setBackgroundPicture(bytes);
} catch (IOException ioe) {
    ioe.printStackTrace();
}

PdfSaveOptions pdfSaveOptions = new PdfSaveOptions();
// Print the background picture in the centre of exported pdf file
pdfSaveOptions.setPrintBackgroundPicture(true);

// Saving workbook to pdf
workbook.save("12-PrintBackgroundPicture.pdf", pdfSaveOptions);

Workbook workbook = new Workbook();
IWorksheet worksheet = workbook.getWorksheets().get(0);
            
//Add a background picture in the worksheet
IBackgroundPicture picture1 = worksheet.getBackgroundPictures().addPictureInPixel("image.png", 10, 10, 250, 150);
IBackgroundPicture picture2 = worksheet.getBackgroundPictures().addPictureInPixel("ConvertShapeToImage.png", 180, 10, 150, 100);

//Set the border style of the destination rectangle.
picture1.getLine().getColor().setRGB(Color.GetRed());
picture1.getLine().setWeight(1);

//The background picture will be resized to fill the destination dimensions.The aspect ratio is not preserved.
picture1.setBackgroundImageLayout(ImageLayout.Tile);

//Sets the rounded corner of the destination rectangle.
picture1.setCornerRadius(50);
//Sets the transparency of the background picture.
picture1.setTransparency(0.5);
picture2.setTransparency(0.5);

//Save to PDF file
workbook.save("ExportBackgroundImageToPDF.pdf");