java itextpdf 设置斜线单元格

可以使用 `PdfPCellEvent` 接口来实现斜线单元格的效果。这个接口提供了一个方法 `cellLayout()`，可以在单元格绘制时添加自定义内容。

下面是一个示例代码，实现了斜线单元格的效果：

import com.itextpdf.awt.geom.AffineTransform;
import com.itextpdf.text.*;
import com.itextpdf.text.pdf.*;

import java.io.FileOutputStream;

public class SlantedCell implements PdfPCellEvent {
    private String text;

    public SlantedCell(String text) {
        this.text = text;
    }

    @Override
    public void cellLayout(PdfPCell cell, Rectangle position, PdfContentByte[] canvases) {
        PdfContentByte canvas = canvases[PdfPTable.TEXTCANVAS];

        float x1 = position.getLeft() + cell.getPaddingLeft();
        float y1 = position.getTop() - cell.getPaddingTop();

        float x2 = position.getRight() - cell.getPaddingRight();
        float y2 = position.getBottom() + cell.getPaddingBottom();

        canvas.saveState();
        canvas.beginText();
        canvas.setColorFill(BaseColor.BLACK);
        canvas.setFontAndSize(BaseFont.createFont(), 12);
        canvas.setTextMatrix(new AffineTransform(1, 0, 0.2f, 1, 0, 0));
        canvas.showTextAligned(Element.ALIGN_LEFT, text, x1, y1, 0);
        canvas.endText();
        canvas.restoreState();

        canvas.saveState();
        canvas.beginText();
        canvas.setColorFill(BaseColor.BLACK);
        canvas.setFontAndSize(BaseFont.createFont(), 12);
        canvas.setTextMatrix(new AffineTransform(1, 0, -0.2f, 1, 0, 0));
        canvas.showTextAligned(Element.ALIGN_LEFT, text, x2, y2, 0);
        canvas.endText();
        canvas.restoreState();
    }

    public static void main(String[] args) throws Exception {
        Document document = new Document();
        PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream("slanted-cell.pdf"));
        document.open();

        PdfPTable table = new PdfPTable(2);
        table.setWidthPercentage(100);
        table.getDefaultCell().setPadding(5);

        PdfPCell cell1 = new PdfPCell(new Phrase("斜线单元格"));
        cell1.setCellEvent(new SlantedCell("斜线单元格"));
        table.addCell(cell1);

        table.addCell(new PdfPCell(new Phrase("普通单元格")));

        document.add(table);
        document.close();
    }
}

这个示例代码创建了一个 `PdfPCellEvent` 接口的实现类 `SlantedCell`，并在 `cellLayout()` 方法中绘制了两条斜线。然后将这个实现类的实例设置给需要添加斜线的单元格的 `cellEvent` 属性即可。