當用相對大小指定表列時，如何從iText獲取列的絕對寬度？我試過的我指定了 3 列，它們的相對寬度為 float，如下所示：PdfPCell cell2;PdfPTable table2 = new PdfPTable(new float[]{(float) 4.5, (float) 0.5, 9});table2.setWidthPercentage(100);我得到了什么我嘗試使用table2.getAbsoluteWidths()[2]但結果是 float 0.0。我所期望的在 PDF 上動態計算表格寬度之后，我想獲得每一列的絕對寬度（最大化）。
1 回答
三國紛爭
TA貢獻1804條經驗 獲得超7個贊
問題及說明
該函數table.getAbsoluteWidths()依賴于必須設置表的totalWidthtable.getTotalWidth() > 0的要求，因此.
這是因為在com.itextpdf.text.pdf.PdfPTable類內部調用了一個方法calculateWidths()，然后計算所有列的絕對寬度：
this.absoluteWidths[k] = this.totalWidth * this.relativeWidths[k] / total;
解決方案
為了確保在檢索relativeWidths數組之前設置了totalWidth，您需要：
（A）設置totalWidth ，如this answer中所述
或(B) 將單元格添加到表格并將表格添加到文檔
解決方案代碼
以下代碼結合了您的算法，以根據列的最大寬度限制跨單元格拆分文本（即長地址或alamat）：
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));
}
}
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