如何使用iTextLibrary在动态pdf中添加页眉和页脚？

Question

我使用iText库动态创建了一个PDF文件,现在我想在PDF页面中添加页眉和页脚,为此我添加了给定的代码:

document.addHeader("My Header Title", "My Header Details");

但在我的PDF页面中,此标题无法设置.什么是我不知道的问题,如果您有任何相关的想法,请分享您的想法.

Answer 1

如果您使用当前的iText版本(即截至目前为5.​​4.x),请查看iText in Action - 2nd Edition中的示例MovieHistory2,其中显示了如何向PDF添加标题(奇数页和偶数页的不同标题)创造它.

最重要的是PdfPageEventHelper实施

/** Inner class to add a header and a footer. */
class HeaderFooter extends PdfPageEventHelper {
    /** Alternating phrase for the header. */
    Phrase[] header = new Phrase[2];
    /** Current page number (will be reset for every chapter). */
    int pagenumber;

    /**
     * Initialize one of the headers.
     * @see com.itextpdf.text.pdf.PdfPageEventHelper#onOpenDocument(
     *      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)
     */
    public void onOpenDocument(PdfWriter writer, Document document) {
        header[0] = new Phrase("Movie history");
    }

    /**
     * Initialize one of the headers, based on the chapter title;
     * reset the page number.
     * @see com.itextpdf.text.pdf.PdfPageEventHelper#onChapter(
     *      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document, float,
     *      com.itextpdf.text.Paragraph)
     */
    public void onChapter(PdfWriter writer, Document document,
            float paragraphPosition, Paragraph title) {
        header[1] = new Phrase(title.getContent());
        pagenumber = 1;
    }

    /**
     * Increase the page number.
     * @see com.itextpdf.text.pdf.PdfPageEventHelper#onStartPage(
     *      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)
     */
    public void onStartPage(PdfWriter writer, Document document) {
        pagenumber++;
    }

    /**
     * Adds the header and the footer.
     * @see com.itextpdf.text.pdf.PdfPageEventHelper#onEndPage(
     *      com.itextpdf.text.pdf.PdfWriter, com.itextpdf.text.Document)
     */
    public void onEndPage(PdfWriter writer, Document document) {
        Rectangle rect = writer.getBoxSize("art");
        switch(writer.getPageNumber() % 2) {
        case 0:
            ColumnText.showTextAligned(writer.getDirectContent(),
                    Element.ALIGN_RIGHT, header[0],
                    rect.getRight(), rect.getTop(), 0);
            break;
        case 1:
            ColumnText.showTextAligned(writer.getDirectContent(),
                    Element.ALIGN_LEFT, header[1],
                    rect.getLeft(), rect.getTop(), 0);
            break;
        }
        ColumnText.showTextAligned(writer.getDirectContent(),
                Element.ALIGN_CENTER, new Phrase(String.format("page %d", pagenumber)),
                (rect.getLeft() + rect.getRight()) / 2, rect.getBottom() - 18, 0);
    }
}

这是这样注册的:

    PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(RESULT));
    HeaderFooter event = new HeaderFooter();
    writer.setBoxSize("art", new Rectangle(36, 54, 559, 788));
    writer.setPageEvent(event);

编辑:根据评论中的要求,onEndPage使用静态标头而不是交替标头的方法的更简单的变体:

    public void onEndPage(PdfWriter writer, Document document)
    {
        Rectangle rect = writer.getBoxSize("art");
        ColumnText.showTextAligned(writer.getDirectContent(),
                Element.ALIGN_RIGHT, new Phrase("My static header text"),
                rect.getRight(), rect.getTop(), 0);
        ColumnText.showTextAligned(writer.getDirectContent(),
                Element.ALIGN_CENTER, new Phrase(String.format("page %d", pagenumber)),
                (rect.getLeft() + rect.getRight()) / 2, rect.getBottom() - 18, 0);
    }