java - 从 PdfPTable 列(iText)获取绝对宽度

Question

当表格列用其相对大小指定时，如何从iText获取列的绝对宽度？

我尝试过的

我指定了 3 列，其相对宽度为 float ，如下所示:

PdfPCell cell2;
PdfPTable table2 =  new PdfPTable(new float[]{(float) 4.5, (float) 0.5, 9});
table2.setWidthPercentage(100);

我得到了什么

我尝试使用table2.getAbsoluteWidths()[2]，但结果是浮点0.0。

我的期望

在 PDF 上动态计算表格宽度后，我想获取每列的绝对宽度(已最大化)。

------------------------ 编辑 ----------------------

实际上，我需要在添加文档之前确定列的宽度，然后替换我的硬编码 float 变量限制。

我有很多数据字符串，并且想在获取最大宽度页面时在另一列中设置并在函数restrictWidthOfFont中进行分割

String fullAlamatPP = "test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test test ";

float restrictions = (float) 330.12103; // this is width of a column from table

String alamatSesuaiKtpPP[] = restrictWidthOfFont(fullAlamatPP, font_body, restrictions);

Phrase p_alamat1_ct = new Phrase(alamatSesuaiKtpPP[0], font_body);
p_alamat1_ct.add(dottedline);
cell2 = new PdfPCell(p_alamat1_ct);
cell2.setBorder(PdfPCell.NO_BORDER);
table2.addCell(cell2);

Phrase p_alamat2_ct = new Phrase(alamatSesuaiKtpPP[1], font_body);
p_alamat2_ct.add(dottedline);
cell2 = new PdfPCell(p_alamat2_ct);
cell2.setBorder(PdfPCell.NO_BORDER);
table2.addCell(cell2);    

private static String[] restrictWidthOfFont(String character, Font font, float restrictions) {
        String results[];
        results = new String[] {"",""};
        String concatChar = " ";
        float widthOfString = 0;
        for (int i = 0; i < character.length();i++) {
            concatChar += character.charAt(i); 
            widthOfString = font.getCalculatedBaseFont(true).getWidthPoint(concatChar, font.getCalculatedSize());
//                System.out.println("widthOfString " + widthOfString);
            if (widthOfString > restrictions) {
                results[0] = concatChar.substring(0, concatChar.length() - 1);
                results[1] = character.substring(i, character.length());
                break;
            }
        }

        if (results[0] == "") {
            results[0] = character;
        }
        return results;
}    

在添加表格文档之前可以获取列的宽度吗？

Answer 1

问题及解释

函数table.getAbsoluteWidths()依赖于必须设置表的 totalWidth 的要求，因此 table.getTotalWidth() > 0 .

这是因为 com.itextpdf.text.pdf.PdfPTable 里面类方法calculateWidths()调用它然后计算所有列的绝对宽度:

this.absoluteWidths[k] = this.totalWidth * this.relativeWidths[k] / total;

解决方案

为了确保在检索relativeWidths数组之前设置了totalWidth，您需要:

• (A) 设置totalWidth，如 this answer 中所述
• 或(B) 将单元格添加到表格中并将表格添加到文档

解决方案代码

以下代码结合您的算法，根据跨单元格的限制分割文本(即长地址或alamat) >列的最大宽度:

import com.itextpdf.text.*;
import com.itextpdf.text.pdf.*;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Arrays;

public class TableWidthSample {

    public static void main(String[] args) {
        Document document = new Document();
        try {
            PdfWriter.getInstance(document, new FileOutputStream("TableColumnWidth.pdf"));
            document.open();

            PdfPTable table = createTableWithRelativeColumnWidths();

            // needed for calculation of getAbsoluteWidths: (A) totalWidth is set for table
            table.setTotalWidth(calculateTableWidthBasedOnPageA4(document, table));
            // now it prints width, because (A)
            printTableWidth(table, "after totalWidth set manually"); // absoluteWidths: [134.4857, 14.942857, 268.9714]

            // long text, that needs to be split among cells (fullAlamatPP)
            String text = "this is a very long text. The text contains a full address. Because the text is too long to be shown in the last cell, it is split.";
            // your CODE to fill text into cells based on restrictions
            addTextAcrossTableCells(table, text);

            document.add(table);

/*
            // need to add filled table to doc (B)
            addToDocumentCellsAndTable(document, table);
            // now it prints width, because (B)
            printTableWidth(table, "after added to doc"); // absoluteWidths: [134.4857, 14.942857, 268.9714]
*/
            document.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static PdfPTable createTableWithRelativeColumnWidths() {
        float[] relativeWidths = {4.5F, 0.5F, 9F};
        PdfPTable table = new PdfPTable(relativeWidths);
        table.setWidthPercentage(100F);
        printTableWidth(table, "after table created"); // absoluteWidths: [0.0, 0.0, 0.0]
        return table;
    }

    private static float calculateTableWidthBasedOnPageA4(Document document, PdfPTable table) {
        return (PageSize.A4.getWidth() - document.leftMargin() - document.rightMargin())
                * table.getWidthPercentage() / 100;
    }

    private static void addToDocumentCellsAndTable(Document document, PdfPTable table) throws DocumentException {
        // needed for calculation of getAbsoluteWidths: (B.1) add cells to table
        table.addCell("Hello");
        table.addCell("World");
        table.addCell("!");
        printTableWidth(table, "after cells added to table"); // absoluteWidths: [0.0, 0.0, 0.0]

        // needed for calculation of getAbsoluteWidths: (B.2) add table to doc
        document.add(table);
    }

    private static void addTextAcrossTableCells(PdfPTable table, String text) throws IOException, DocumentException {
        // restrictions; this is width of a column from table
        float maxColumnWidth = table.getAbsoluteWidths()[2]; // 330.12103F;
        System.out.println("use width of third column as max: " + maxColumnWidth);
        // sample font used for calculation of text-width
        Font font = new Font(BaseFont.createFont("Courier", BaseFont.CP1250, true), 12);

        // alamatSesuaiKtpPP
        String splitText[] = getTextPartsUsingFontWithMaxWidth(text, font, maxColumnWidth);
        String dottedLine = "..";
        table.addCell("Alamat / Address:");

        // p_alamat1_ct
        Phrase phrase1 = new Phrase(splitText[0], font);
        phrase1.add(dottedLine);
        PdfPCell cell1 = new PdfPCell(phrase1);
        cell1.setBackgroundColor(BaseColor.LIGHT_GRAY);
        cell1.setBorder(PdfPCell.NO_BORDER);
        table.addCell(cell1);

        // p_alamat2_ct
        Phrase phrase2 = new Phrase(splitText[1], font);
        phrase2.add(dottedLine);
        PdfPCell cell2 = new PdfPCell(phrase2);
        cell2.setBorder(PdfPCell.NO_BORDER);
        table.addCell(cell2);
    }

    private static String[] getTextPartsUsingFontWithMaxWidth(String text, Font font, float maxWidth) {
        String results[] = new String[] {"",""};
        String firstPartOfText = " ";
        float widthOfText = 0;
        for (int i = 0; i < text.length();i++) {
            firstPartOfText += text.charAt(i);
            widthOfText = font.getCalculatedBaseFont(true).getWidthPoint(firstPartOfText, font.getCalculatedSize());
            System.out.printf("%d: widthOfText: %f\n", i, widthOfText);
            if (widthOfText > maxWidth) {
                results[0] = firstPartOfText.substring(0, firstPartOfText.length() - 1);
                results[1] = text.substring(i); // second argument "text.length()" is not needed
                break;
            }
        }

        if (results[0] == "") {
            results[0] = text;
        }
        return results;
    }

    private static void printTableWidth(PdfPTable table, String labelText) {
        float[] absoluteWidths = table.getAbsoluteWidths();
        System.out.println(labelText + "> getAbsoluteWidths: " + Arrays.toString(absoluteWidths));
    }
}

另请参阅

How to make PdfPTable calculate column-width dynamically