我打开一个现有的 pdf。检查保护并询问密码是否受保护并使用以下命令打开它:
PdfReader pdfReader = null;
Stream outputStream = null;
PdfStamper pdfStamper = null;
try
{
pdfReader = GetPdfReaderObject();
outputStream = new FileStream(filePathDestination, FileMode.Create, FileAccess.Write, FileShare.None);
pdfStamper = new PdfStamper(pdfReader, outputStream);
PdfLayer layer = new PdfLayer("watermark", pdfStamper.Writer);
for (int pageIndex = 1; pageIndex <= pdfReader.NumberOfPages; pageIndex++) {
pdfStamper.FormFlattening = false;
iTextSharp.text.Rectangle pageRectangle = pdfReader.GetPageSizeWithRotation(pageIndex);
PdfContentByte pdfData = pdfStamper.GetOverContent(pageIndex);
pdfData.BeginLayer(layer);
PdfGState graphicsState = new PdfGState();
graphicsState.FillOpacity = 0.5F;
pdfData.SetGState(graphicsState);
pdfData.BeginText();
iTextSharp.text.Image watermarkImage = iTextSharp.text.Image.GetInstance(System.Drawing.Image.FromFile(watermarkImagePath), ImageFormat.Png);
float width = pageRectangle.Width;
float height = pageRectangle.Height;
watermarkImage.SetAbsolutePosition(width / 2 - watermarkImage.Width / 2, height / 2 - watermarkImage.Height / 2);
pdfData.AddImage(watermarkImage);
pdfData.EndText();
pdfData.EndLayer();
}
}
pdfStamper.Close();
outputStream.Close();
outputStream.Dispose();
pdfReader.Close();
pdfReader.Dispose();
} catch (Exception e) {
....
}
}
在我修改后,我保存了它,但保护被破坏了。
为什么保护被破坏?如何保存原始文档的保护并将其添加到我修改过的文档中。
问候