我正在尝试使用Apache-POI将图像插入Excel工作表中，该工作表的左上角位于大字体（Calibri-32）行的中间。
使用众所周知的公式，我发现dy1中的XSSFClientAnchor值应约为260,000。
但是，当打开Excel文件时，出现错误，提示内容模糊不清。
接受警告后，影像仍然正确显示。
经过一些测试，我发现dy的最大值似乎是190,500，而没有从Excel中得到错误。
我使用的字体导致行高为55像素。
因此，该行的中途是0.5*55*Units.EMU_PER_PIXEL=261,938。
当使用较小的字体但使图像在行尾附近开始时，会发生相同的问题。
在所有情况下，如果dy1的值都大于190500，则会出现错误。
有人知道吗？
更新：
我从xlsx文件中提取了xml，并且发现某个地方的cy值为负。我不太熟悉xlsx的内容，但我希望它对某些人有用：
<xdr:wsDr xmlns:xdr="http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing" xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
<xdr:twoCellAnchor editAs="oneCell">
<xdr:from>
<xdr:col>2</xdr:col>
<xdr:colOff>147637</xdr:colOff>
<xdr:row>0</xdr:row>
<xdr:rowOff>261937</xdr:rowOff>
</xdr:from>
<xdr:to>
<xdr:col>5</xdr:col>
<xdr:colOff>2309812</xdr:colOff>
<xdr:row>13</xdr:row>
<xdr:rowOff>14287</xdr:rowOff>
</xdr:to>
<xdr:pic>
<xdr:nvPicPr>
<xdr:cNvPr id="1" name="Picture 1" descr="Picture"/>
<xdr:cNvPicPr>
<a:picLocks noChangeAspect="true"/>
</xdr:cNvPicPr>
</xdr:nvPicPr>
<xdr:blipFill>
<a:blip r:embed="rId1"/>
<a:stretch>
<a:fillRect/>
</a:stretch>
</xdr:blipFill>
<xdr:spPr>
<a:xfrm>
<a:off x="147637" y="261937"/>
<a:ext cx="195263" cy="-71437"/>
</a:xfrm>
<a:prstGeom prst="rect">
<a:avLst/>
</a:prstGeom>
</xdr:spPr>
</xdr:pic>
<xdr:clientData/>
</xdr:twoCellAnchor>
</xdr:wsDr>
更新2：
以下代码显示该错误。如果dy1大于190500并且row2等于row1 + 1，则会发生这种情况
/**********************************************************************************************************************
* Package specification
*********************************************************************************************************************/
package test;
/**********************************************************************************************************************
* Import definitions
*********************************************************************************************************************/
import java.awt.Desktop;
import java.io.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.util.*;
import org.apache.poi.xssf.streaming.*;
import org.apache.poi.xssf.usermodel.*;
/**********************************************************************************************************************
* This class implements a Minimal, Complete and Verifiable example for the problem of the maximum dy value for the
* {@link XSSFClientAnchor}.
*********************************************************************************************************************/
public class TestPictureOffset
{
/********************************************************************************************************************
* This constants represents the name of the file with the picture to import within the sheet.
*******************************************************************************************************************/
private static final String FILENAME_PICTURE = "./excel.png";
/********************************************************************************************************************
* These constants represents the width and height of the big cell within the sheet.
*******************************************************************************************************************/
private static final short BIG_CELL_COLUMN_WIDTH_IN_PIXELS = 317;
private static final short BIG_CELL_ROW_HEIGHT_IN_PIXELS = 56;
/********************************************************************************************************************
* This constants represents the default height of a cell within the sheet.
*******************************************************************************************************************/
private static final short DEFAULT_ROW_HEIGHT_IN_PIXELS = 20;
/********************************************************************************************************************
* This method places the specified picture on the sheet.
*******************************************************************************************************************/
private static void setPicture(int picture_index,
SXSSFSheet sheet)
{
// -----------------
// Initialize anchor
// -----------------
XSSFClientAnchor anchor;
anchor = (XSSFClientAnchor)sheet.getWorkbook().getCreationHelper().createClientAnchor();
anchor.setAnchorType(XSSFClientAnchor.AnchorType.MOVE_AND_RESIZE);
// -----------------------------
// Set position
// THIS IS WHERE THE FUN HAPPENS
// -----------------------------
anchor.setCol1(1);
anchor.setRow1(0);
anchor.setDx1((int)(0.5 * BIG_CELL_COLUMN_WIDTH_IN_PIXELS * Units.EMU_PER_PIXEL));
anchor.setDy1((int)(0.4 * BIG_CELL_ROW_HEIGHT_IN_PIXELS * Units.EMU_PER_PIXEL));
anchor.setCol2(anchor.getCol1() + 1);
anchor.setRow2(anchor.getRow1() + 1); // Fails if dy1 > 190500
//anchor.setRow2(anchor.getRow1() + 2); // OK independently from dy1
anchor.setDx2(0);
anchor.setDy2(0);
// ----------------------
// Show some measurements
// ----------------------
System.out.println("Got dy1: " + anchor.getDy1());
System.out.println("Maximum dy in default cell: " + (DEFAULT_ROW_HEIGHT_IN_PIXELS * Units.EMU_PER_PIXEL));
// ----------------
// Draw the picture
// ----------------
sheet.createDrawingPatriarch().createPicture(anchor, picture_index);
} // setPicture
/********************************************************************************************************************
* This method runs the application.
*******************************************************************************************************************/
private static void run()
throws Exception
{
// ---------------
// Create workbook
// ---------------
SXSSFWorkbook workbook;
workbook = new SXSSFWorkbook();
workbook.setCompressTempFiles(true);
// ------------
// Create sheet
// ------------
SXSSFSheet sheet;
sheet = workbook.createSheet("TestSheet");
sheet.trackAllColumnsForAutoSizing();
// --------------------------
// Create style with big font
// --------------------------
Font font;
XSSFCellStyle style;
font = workbook.createFont();
font.setFontHeightInPoints((short)32);
style = (XSSFCellStyle)workbook.createCellStyle();
style.setFont(font);
// -------------------
// Write something big
// -------------------
SXSSFRow row;
SXSSFCell cell;
row = sheet.createRow(0);
cell = row.createCell(1);
cell.setCellStyle(style);
cell.setCellValue("Hello everybody");
// -----------------------
// Auto resize this column
// -----------------------
sheet.autoSizeColumn(1);
// ------------
// Load picture
// ------------
InputStream input_stream;
byte[] bytes;
input_stream = new FileInputStream(FILENAME_PICTURE);
bytes = IOUtils.toByteArray(input_stream);
input_stream.close();
// ---------------
// Add to workbook
// ---------------
int picture_index;
picture_index = workbook.addPicture(bytes, SXSSFWorkbook.PICTURE_TYPE_PNG);
// -------------------------
// Position picture in sheet
// -------------------------
setPicture(picture_index, sheet);
// -------------
// Save workbook
// -------------
File output_file;
FileOutputStream output_stream;
output_file = new File("testxls.xlsx");
output_stream = new FileOutputStream(output_file);
workbook.write(output_stream);
output_stream.close();
workbook.close();
// -------
// Open it
// -------
Desktop.getDesktop().open(output_file);
} // run
/********************************************************************************************************************
* M A I N
*******************************************************************************************************************/
public static void main(String[] args)
{
try
{
run();
}
catch (Exception exception)
{
exception.printStackTrace();
}
} // main
} // class TestPictureOffset
最佳答案
因此，我们需要确定负数cy的来源。
首先：您不应对BIG_CELL_COLUMN_WIDTH_IN_PIXELS和BIG_CELL_ROW_HEIGHT_IN_PIXELS使用常量。而是与apache poi一样，并使用sheet.getColumnWidthInPixels和ImageUtils.getRowHeightInPixels计算宽度和高度。
并且您需要根据字体高度设置行高。否则，该行将保持默认高度，直到Excel在视图中呈现工作表。并且在默认的行高中，如果dy1大于190500，则dy1在该行的外部。因此，对于该行，它不是有效的XSSFDrawing.java。xfrm中有private CTTransform2D createXfrm(XSSFClientAnchor anchor)，可计算包含cy的cy。可以看到，只有height + anchor.getDy2()低于anchor.getDy1()时，才会出现负的XSSF。
使用SXSSF就足够了。但是使用private CTTransform2D createXfrm(XSSFClientAnchor anchor)用ImageUtils.getRowHeightInPixels(sheet, row)计算中的行高似乎是错误的。我怀疑这是因为流方式导致表格中行高度未知。因此，我们需要一种解决方法。将默认行高设置为大字体所需的大，然后设置图片，然后重置默认行高。
以下对我有用：
/**********************************************************************************************************************
* Import definitions
*********************************************************************************************************************/
import java.awt.Desktop;
import java.io.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.util.*;
import org.apache.poi.xssf.streaming.*;
import org.apache.poi.xssf.usermodel.*;
import org.apache.poi.ss.util.ImageUtils;
/**********************************************************************************************************************
* This class implements a Minimal, Complete and Verifiable example for the problem of the maximum dy value for the
* {@link XSSFClientAnchor}.
*********************************************************************************************************************/
public class TestPictureOffset
{
/********************************************************************************************************************
* This constants represents the name of the file with the picture to import within the sheet.
*******************************************************************************************************************/
private static final String FILENAME_PICTURE = "./excel.png";
/********************************************************************************************************************
* These constants represents the width and height of the big cell within the sheet.
*******************************************************************************************************************/
// Don't do that. Instead do the same as apache poi does and use
// sheet.getColumnWidthInPixels and
// ImageUtils.getRowHeightInPixels to calculate width and height
private static final short BIG_CELL_COLUMN_WIDTH_IN_PIXELS = 317;
private static final short BIG_CELL_ROW_HEIGHT_IN_PIXELS = 56;
/********************************************************************************************************************
* This constants represents the default height of a cell within the sheet.
*******************************************************************************************************************/
private static final short DEFAULT_ROW_HEIGHT_IN_PIXELS = 20;
/********************************************************************************************************************
* This method places the specified picture on the sheet.
*******************************************************************************************************************/
private static void setPicture(int picture_index,
Sheet sheet)
{
// -----------------
// Initialize anchor
// -----------------
ClientAnchor anchor;
anchor = sheet.getWorkbook().getCreationHelper().createClientAnchor();
anchor.setAnchorType(ClientAnchor.AnchorType.MOVE_AND_RESIZE);
// -----------------------------
// Set position
// THIS IS WHERE THE FUN HAPPENS
// -----------------------------
anchor.setCol1(1);
anchor.setRow1(0);
//anchor.setDx1((int)(0.5 * BIG_CELL_COLUMN_WIDTH_IN_PIXELS * Units.EMU_PER_PIXEL));
//anchor.setDy1((int)(0.4 * BIG_CELL_ROW_HEIGHT_IN_PIXELS * Units.EMU_PER_PIXEL));
anchor.setDx1((int)(0.5 * sheet.getColumnWidthInPixels(1) * Units.EMU_PER_PIXEL));
anchor.setDy1((int)(0.4 * ImageUtils.getRowHeightInPixels(sheet, 0) * Units.EMU_PER_PIXEL));
anchor.setCol2(anchor.getCol1() + 1);
anchor.setRow2(anchor.getRow1() + 1); // Fails if dy1 > 190500
//anchor.setRow2(anchor.getRow1() + 2); // OK independently from dy1
anchor.setDx2(0);
anchor.setDy2(0);
// ----------------------
// Show some measurements
// ----------------------
System.out.println("Got dy1: " + anchor.getDy1());
System.out.println("Maximum dy in default cell: " + (DEFAULT_ROW_HEIGHT_IN_PIXELS * Units.EMU_PER_PIXEL));
// ----------------
// Draw the picture
// ----------------
sheet.createDrawingPatriarch().createPicture(anchor, picture_index);
} // setPicture
/********************************************************************************************************************
* This method runs the application.
*******************************************************************************************************************/
private static void run()
throws Exception
{
// ---------------
// Create workbook
// ---------------
SXSSFWorkbook workbook;
workbook = new SXSSFWorkbook();
workbook.setCompressTempFiles(true);
// ------------
// Create sheet
// ------------
SXSSFSheet sheet;
sheet = workbook.createSheet("TestSheet");
sheet.trackAllColumnsForAutoSizing();
// --------------------------
// Create style with big font
// --------------------------
Font font;
CellStyle style;
font = workbook.createFont();
font.setFontHeightInPoints((short)32);
style = workbook.createCellStyle();
style.setFont(font);
// -------------------
// Write something big
// -------------------
SXSSFRow row;
SXSSFCell cell;
row = sheet.createRow(0);
cell = row.createCell(1);
cell.setCellStyle(style);
cell.setCellValue("Hello everybody");
// -----------------------
// Set row heigth according to the fonts height
// -----------------------
row.setHeightInPoints(workbook.getFontAt(style.getFontIndex()).getFontHeightInPoints()*1.275f);
// -----------------------
// Auto resize this column
// -----------------------
sheet.autoSizeColumn(1);
// ------------
// Load picture
// ------------
InputStream input_stream;
byte[] bytes;
input_stream = new FileInputStream(FILENAME_PICTURE);
bytes = IOUtils.toByteArray(input_stream);
input_stream.close();
// ---------------
// Add to workbook
// ---------------
int picture_index;
picture_index = workbook.addPicture(bytes, SXSSFWorkbook.PICTURE_TYPE_PNG);
// -------------------------
// Position picture in sheet
// -------------------------
// Workaround for SXSSFSheet which has not the correct row height in
// private CTTransform2D createXfrm(XSSFClientAnchor anchor)
// because of the streaming manner.
// So set default row height that big:
sheet.setDefaultRowHeight(sheet.getRow(0).getHeight());
// set the picture then:
setPicture(picture_index, sheet);
// and reset the default row height after that:
sheet.setDefaultRowHeight((short)(15*20));
// -------------
// Save workbook
// -------------
File output_file;
FileOutputStream output_stream;
output_file = new File("testxls.xlsx");
output_stream = new FileOutputStream(output_file);
workbook.write(output_stream);
output_stream.close();
workbook.close();
workbook.dispose();
// -------
// Open it
// -------
Desktop.getDesktop().open(output_file);
} // run
/********************************************************************************************************************
* M A I N
*******************************************************************************************************************/
public static void main(String[] args)
{
try
{
run();
}
catch (Exception exception)
{
exception.printStackTrace();
}
} // main
} // class TestPictureOffset