如何使用iTextSharp将缩放级别设置为pdf？ [英] How to set zoom level to pdf using iTextSharp?

问题描述

我需要使用iTextSharp将缩放级别设置为75％到pdf文件。我正在使用以下代码来设置缩放级别。

I need to set the zoom level 75% to pdf file using iTextSharp. I am using following code to set the zoom level.

PdfReader reader = new PdfReader("input.pdf".ToString());
iTextSharp.text.Document doc = new iTextSharp.text.Document(reader.GetPageSize(1));
doc.OpenDocument();
PdfWriter writer = PdfWriter.GetInstance(doc, new FileStream("Zoom.pdf", FileMode.Create));
PdfDestination pdfDest = new PdfDestination(PdfDestination.XYZ, 0, doc.PageSize.Height, 0.75f);
doc.Open();
PdfAction action = PdfAction.GotoLocalPage(1, pdfDest, writer);
writer.SetOpenAction(action);
doc.Close();

但是我收到错误第1页是请求但文档只有0页 doc.Close（）;

But I am getting the error "the page 1 was request but the document has only 0 pages" in the doc.Close();

推荐答案

你需要使用 PdfStamper （由mkl表示）而不是 PdfWriter （由Chris Haas明确表示）。请查看 AddOpenAction 示例：

You need to use PdfStamper (as indicated by mkl) instead of PdfWriter (as made clear by Chris Haas). Please take a look at the AddOpenAction example:

public void manipulatePdf(String src, String dest) throws IOException, DocumentException {
    PdfReader reader = new PdfReader(src);
    PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
    PdfDestination pdfDest = new PdfDestination(PdfDestination.XYZ, 0, reader.getPageSize(1).getHeight(), 0.75f);
    PdfAction action = PdfAction.gotoLocalPage(1, pdfDest, stamper.getWriter());
    stamper.getWriter().setOpenAction(action);
    stamper.close();
    reader.close();
}

结果是以缩放系数75％打开的PDF 。

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