如何在iTextSharp中创建目录 [英] How to create Table Of Contents in iTextSharp

问题描述

我需要使用页码创建内容表，但我不知道如何。下一个格式：

  heading1 ----------------页码
 subHeading1 ---------------页码
 subHeading2 ---------------页码
 heading2 ----- ------------页码
  

我读了几篇文章并没有'理解。特别是，我的意思是

您可以清楚地看到标题下的标题和内容。在我们添加了所有内容后，我们开始一个新页面，并添加一个目录：

目录由一系列键值对组成，其中键是标题，值是页码。我们在页面事件中创建此列表：

  public class TOCEvent extends PdfPageEventHelper {
 
 protected List< SimpleEntry< String，Integer>> toc = new ArrayList<>（）; 
 
 @Override 
 public void onGenericTag（PdfWriter writer，Document document，Rectangle rect，String text）{
 toc.add（new SimpleEntry（text，writer.getPageNumber（）） ）; 
} 
 
 public List getTOC（）{
 return toc; 
} 
} 
  

我们使用此页面事件：

  public void createPdf（String dest）throws IOException，DocumentException {
 Document document = new Document（）; 
 PdfWriter writer = PdfWriter.getInstance（document，new FileOutputStream（dest））; 
 TOCEvent event = new TOCEvent（）; 
 writer.setPageEvent（event）; 
 document.open（）; 
 for（int i = 0; i< 10; i ++）{
 String title =This is title+ i; 
 Chunk c = new Chunk（title，titleFont）; 
 c.setGenericTag（title）; 
 document.add（新的（c）段）; 
 for（int j = 0; j< 50; j ++）{
 document.add（new Paragraph（Line+ j +title of title + + i））; 
} 
} 
 document.newPage（）; 
 document.add（新段落（目录，titleFont））; 
 Chunk dottedLine = new Chunk（new DottedLineSeparator（））; 
 List< SimpleEntry< String，Integer>> entries = event.getTOC（）; 
第p段; 
 for（SimpleEntry< String，Integer> entry：entries）{
 p = new Paragraph（entry.getKey（））; 
 p.add（dottedLine）; 
 p.add（String.valueOf（entry.getValue（）））; 
 document.add（p）; 
} 
 document.close（）; 
} 
  

首先，我们创建一个事件实例，并将其声明给作者：

  TOCEvent event = new TOCEvent（）; 
 writer.setPageEvent（event）; 
  

我们使用 setGenericTag（）标记标题：

  String title =This is title+ i; 
 Chunk c = new Chunk（title，titleFont）; 
 c.setGenericTag（title）; 
 document.add（新的（c）段）; 
  

我们完成添加内容后，我们会收到所有条目：

  List< SimpleEntry< String，Integer>> entries = event.getTOC（）; 
  

我们遍历此列表并撰写段落对于每个条目：

  for（SimpleEntry< String，Integer> entry：entries）{
p = new Paragraph（ entry.getKey（））; 
 p.add（dottedLine）; 
 p.add（String.valueOf（entry.getValue（）））; 
 document.add（p）; 
} 
  

没有人可以说这很难。事件类只需少于10行代码。添加对副标题的支持将添加一些行，但这也不难。这是建立树结构的问题，并在必要时引入一些缩进。

I need create Table Of Content with page numbers, but i don't know how. Next format:

heading1 ----------------page number  
  subHeading1---------------page number
  subHeading2---------------page number  
heading2-----------------page number  

I read few articles and didn't understand.In particular, I mean this article, where "Named destinations" and "GoTo actions" I think is useful for me, but I don't know how it doing in iTextSharp.

In my code I have got few "Chapter" and "Section", and I want take it and create TOC. How I understood, I need to use PdfPageEventHelper and OnChapter.

解决方案

You've probably implemented this yourself by name, but I made a small example myself for the sake of completeness.

Please take a look at the CreateTOC example. It creates a PDF with some random text:

You can clearly see the titles and the content under the titles. After we have added all our content, we start a new page, and we add a table of contents:

The table of contents is composed by a series of key-value pairs, where the key is the title and the value is the page number. We create this list in a page event:

public class TOCEvent extends PdfPageEventHelper {

    protected List<SimpleEntry<String, Integer>> toc = new ArrayList<>();

    @Override
    public void onGenericTag(PdfWriter writer, Document document, Rectangle rect, String text) {
        toc.add(new SimpleEntry(text, writer.getPageNumber()));
    }

    public List getTOC() {
        return toc;
    }
}

We use this page event like this:

public void createPdf(String dest) throws IOException, DocumentException {
    Document document = new Document();
    PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest));
    TOCEvent event = new TOCEvent();
    writer.setPageEvent(event);
    document.open();
    for (int i = 0; i < 10; i++) {
        String title = "This is title " + i;
        Chunk c = new Chunk(title, titleFont);
        c.setGenericTag(title);
        document.add(new Paragraph(c));
        for (int j = 0; j < 50; j++) {
            document.add(new Paragraph("Line " + j + " of title " + i));
        }
    }
    document.newPage();
    document.add(new Paragraph("Table of Contents", titleFont));
    Chunk dottedLine = new Chunk(new DottedLineSeparator());
    List<SimpleEntry<String, Integer>> entries = event.getTOC();
    Paragraph p;
    for (SimpleEntry<String, Integer> entry : entries) {
        p = new Paragraph(entry.getKey());
        p.add(dottedLine);
        p.add(String.valueOf(entry.getValue()));
        document.add(p);
    }
    document.close();
}

First we create an instance of the event and we declare it to the writer:

TOCEvent event = new TOCEvent();
writer.setPageEvent(event);

We mark the titles using setGenericTag():

String title = "This is title " + i;
Chunk c = new Chunk(title, titleFont);
c.setGenericTag(title);
document.add(new Paragraph(c));

Once we've finished adding the content, we get all the entries:

List<SimpleEntry<String, Integer>> entries = event.getTOC();

We loop over this list and compose a Paragraph for every entry:

for (SimpleEntry<String, Integer> entry : entries) {
    p = new Paragraph(entry.getKey());
    p.add(dottedLine);
    p.add(String.valueOf(entry.getValue()));
    document.add(p);
}

No one can argue that this was difficult. The event class takes less than 10 lines of code. Adding support for subheadings will add a handful of lines, but that shouldn't be difficult too. It's a matter of building a tree structure, and introducing some indentation where necessary.

这篇关于如何在iTextSharp中创建目录的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！