Question

我正在使用java类创建一个大的excel。 Excel包含存储字符串的合并单元格。字符串的长度非常大，我动态地得到这个字符串。我需要增加合并单元格的高度，以便完整的字符串适合该单元格。我已经尝试使用＆＃34;换文本＆＃34;，它包装文本但是没有增加合并单元格的高度，因为在excel中看不到完整的字符串。我正在使用的Java类是：

XSSFWorkbook
XSSFSheet
XSSFRow
XSSFCell
XSSFCellStype

以及其他所需的依赖类。有没有办法如何根据单元格值增加合并单元格的高度。

Answer 1

让您了解如何计算所需行高的挑战。

我们可以使用Sheet.getColumnWidth(int)获取列的字符宽度的列宽。但这并不准确，因为它只适用于数字字形：1,2,3,4,5,6,7,8,9,0。在真实字体中，有字形（。，|，l，...）需要更少的宽度。因此，这个结果将更加不准确，因为文本中使用了这种较小宽度的字形。

我们可能会通过一个因子来修正列宽。我用5/4。但这在很大程度上取决于所使用的语言。

然后我们可以计算所需的行数，然后通过获取一行使用的默认行高并将其乘以所需的行数来获得所需的行高。

import java.io.FileOutputStream;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.apache.poi.ss.util.CellRangeAddress;

public class CreateExcelCellWrapText {

 public static void main(String[] args) throws Exception {
  XSSFWorkbook workbook = new XSSFWorkbook();

  CellStyle cellstyle = workbook.createCellStyle();
  cellstyle.setWrapText(true);

  Sheet sheet = workbook.createSheet();

//__________________________not merged = height is auto sized

  Row row = sheet.createRow(0);

  Cell cell = row.createCell(2);
  cell.setCellValue("String cell content\nhaving line wrap.");
  cell.setCellStyle(cellstyle);

//__________________________merged = height is not auto sized

  row = sheet.createRow(2);

  cell = row.createCell(2);
  cell.setCellValue("String cell content\nhaving line wrap.");
  cell.setCellStyle(cellstyle);

  CellRangeAddress cellRangeAddress = new CellRangeAddress(2, 2, 2, 3);
  sheet.addMergedRegion(cellRangeAddress);

//__________________________merged with calculated height

  row = sheet.createRow(4);

  String text = "String cell content\nhaving line wrap.\nIt has new line marks and then a long text without new line marks.\nFollowed by short text part.\n\n\nGreetings";

  cell = row.createCell(2);
  cell.setCellValue(text);
  cell.setCellStyle(cellstyle);

  cellRangeAddress = new CellRangeAddress(4, 4, 2, 3);
  sheet.addMergedRegion(cellRangeAddress);

  //get the column width in character widths for the merged columns
  //this is not really accurate since it only is for number glyphs: 1,2,3,4,5,6,7,8,9,0
  //in true type fonts there are glyps (., |, l, ...) which need much less width
  int colwidthinchars = (sheet.getColumnWidth(2) + sheet.getColumnWidth(3)) / 256;
System.out.println(colwidthinchars);
  //correct the colwidthinchars by a factor 5/4 (highly dependent on the language used)
  colwidthinchars = Math.round(colwidthinchars * 5f/4f);
System.out.println(colwidthinchars);

  //calculate the needed rows dependent on the text and the column width in character widths
  String[] chars = text.split("");
  int neededrows = 1;
  int counter = 0;
  for (int i = 0; i < chars.length; i++) {
   counter++;
   if (counter == colwidthinchars) {
System.out.println("new line because of charcter count");
    neededrows++;
    counter = 0;
   } else if ("\n".equals(chars[i])) {
System.out.println("new line because of new line mark");
    neededrows++;
    counter = 0;
   }
  }

System.out.println(neededrows);

  //get default row height
  float defaultrowheight = sheet.getDefaultRowHeightInPoints();
System.out.println(defaultrowheight);

  row.setHeightInPoints(neededrows * defaultrowheight);

  workbook.write(new FileOutputStream("CreateExcelCellWrapText.xlsx"));
  workbook.close();
 }
}

这是有效的，因为使用了默认字体和字体大小。当使用不同的字体和不同的字体大小时，挑战会增加到无穷大; - ）。

有关在JTextPane中呈现格式化文字以获取首选高度的示例，请参阅How to get the needed height of a multi line rich-text field (any font, any font size) having defined width using Java?。

如何使用合并单元格值大于单元格宽度的Apache-POI来增加excel行的高度？

1 个答案: