使用iTEXT创建Java PDF

Question

如何使用java在iText中创建带背景色的段落。 我尝试过使用Chunk，但是它的高亮文本的颜色达到了它的长度，并且在行之间没有应用bg颜色。

Answer 1

你的任务是创建与背景颜色一个段落（特别是线之间的不间断），可以通过页面事件监听器本地存储段落的起始位置，并尽快绘制背景矩形作为段落的结尾来实现发信号通知：

public class ParagraphBackground extends PdfPageEventHelper 
{ 
    public BaseColor color = BaseColor.YELLOW; 
    public void setColor(BaseColor color) 
    { 
     this.color = color; 
    } 

    public boolean active = false; 
    public void setActive(boolean active) 
    { 
     this.active = active; 
    } 

    public float offset = 5; 
    public float startPosition; 

    @Override 
    public void onStartPage(PdfWriter writer, Document document) 
    { 
     startPosition = document.top(); 
    } 

    @Override 
    public void onParagraph(PdfWriter writer, Document document, float paragraphPosition) 
    { 
     this.startPosition = paragraphPosition; 
    } 

    @Override 
    public void onEndPage(PdfWriter writer, Document document) 
    { 
     if (active) 
     { 
      PdfContentByte cb = writer.getDirectContentUnder(); 
      cb.saveState(); 
      cb.setColorFill(color); 
      cb.rectangle(document.left(), document.bottom() - offset, 
       document.right() - document.left(), startPosition - document.bottom()); 
      cb.fill(); 
      cb.restoreState(); 
     } 
    } 

    @Override 
    public void onParagraphEnd(PdfWriter writer, Document document, float paragraphPosition) 
    { 
     if (active) 
     { 
      PdfContentByte cb = writer.getDirectContentUnder(); 
      cb.saveState(); 
      cb.setColorFill(color); 
      cb.rectangle(document.left(), paragraphPosition - offset, 
       document.right() - document.left(), startPosition - paragraphPosition); 
      cb.fill(); 
      cb.restoreState(); 
     } 
    } 
} 

（ParagraphBackground.java）

每当此页面事件监听器在段落的一端设置为活动，段落背景着色。

它可用于这样的：

@Test 
public void testParagraphBackgroundEventListener() throws DocumentException, FileNotFoundException 
{ 
    Document document = new Document(); 
    PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("document-with-paragraph-backgrounds.pdf")); 
    ParagraphBackground back = new ParagraphBackground(); 
    writer.setPageEvent(back); 
    document.open(); 
    document.add(new Paragraph("Hello,")); 
    document.add(new Paragraph("In this document, we'll add several paragraphs that will trigger page events. As long as the event isn't activated, nothing special happens, but let's make the event active and see what happens:")); 
    back.setActive(true); 
    document.add(new Paragraph("This paragraph now has a background. Isn't that fantastic? By changing the event, we can even draw a border, change the line width of the border and many other things. Now let's deactivate the event.")); 
    back.setActive(false); 
    document.add(new Paragraph("This paragraph no longer has a background.")); 
    document.close(); 
} 

（ColorParagraphBackground.java）

结果看起来像这样：

---

积分

这实际上是一个Bruno Lowagie的answer to "How to add border to paragraph in itext pdf library in java?" rip-off与填充，而不是笔触背景矩形的小改动。他甚至已经回来了，虽然这样的应用程序，他的示例程序写道：

本段现在有一个边框。这不是太棒了吗？ 通过改变的情况下，我们甚至可以提供一个背景色