How to get rid of top padding in PdfPCell, iText 5

Question

I am creating labels (as in Avery labels) using iText 5 tables. Positioning of label elements requires some very tight tolerances in order to fit everything on the label. My problem is that I have various zones on the label as PdfPCells. I need to fit text into these zones with 0 wasted space. But I always seem to have extra space at the top of the cell. This is best illustrated by using .setVerticalAlignment(Element.ALIGN_TOP); which does not bring the text to the top of my cell.

I'd show image but apparently I'm not allowed.

How do I get rid of this space?

package actions.test;

import java.io.FileOutputStream;

import com.itextpdf.text.BaseColor;
import com.itextpdf.text.Document;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;

public class PdfCellTest
{
  public static void main(String[] args) throws Exception {

    System.out.println("Cell Test");
    BaseFont bf = BaseFont.createFont
(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.EMBEDDED);
    Font companyFont =new Font(bf);
    companyFont.setSize(10.5f);
    companyFont.setColor(BaseColor.BLUE);
    companyFont.setStyle(Font.BOLD);

    Document document = new Document();

    PdfWriter writer = PdfWriter.getInstance(document,
 new FileOutputStream("c:\\temp\\celltest.pdf"));

    document.open();

    PdfPTable main =  new PdfPTable(1);
    main.setWidthPercentage(30);

    Phrase companyPhrase = new Phrase("My Company Name, LLC",companyFont);

    PdfPCell companyCell = new PdfPCell(companyPhrase);
    companyCell.setHorizontalAlignment(Element.ALIGN_CENTER);
    companyCell.setVerticalAlignment(Element.ALIGN_TOP);
    companyCell.setBorder(Rectangle.BOX);
    companyCell.setBorderColor(BaseColor.RED);
    companyCell.setPadding(0);
    companyCell.setFixedHeight(10.5f);
    companyCell.setBackgroundColor(BaseColor.WHITE);
    main.addCell(companyCell);

    document.add(main);
    document.close();

  }
}

Answer 1

您非常接近解决方案。您设置的所有属性都正常，现在尝试添加：

companyCell.setUseAscender(true);
companyCell.setUseDescender(true);

这些方法有什么作用？它们考虑了存储在正在使用的字体中的度量。您谈论的是顶部填充，但您会注意到“下降器”也会对底部填充产生很好的影响。

顶部的“填充”并不是真正的填充。是“领头羊”。您使用的是默认字体，即 Helvetica 12pt。默认行距是字体大小的 1.5 倍。那是18pt。您正在文本模式下工作，这意味着您可以在单元格级别定义行距（与在元素级别定义行距的复合模式相反）。例如：您可以像这样从顶部的“填充”中删除 4pt：

companyCell.setLeading(14);

重要提示：这也将减少不同行之间的间距。如果这不是一个选项，您可能需要切换到复合模式。