Question

According to How can columns be set to 'autosize' in Excel documents created with NPOI? I did so:

foreach (DataColumn column in dataTable.Columns)
{
   int rowIndex = 0;
   foreach (DataRow row in dataTable.Rows)
   {
      HSSFRow dataRow = sheet.CreateRow(rowIndex);
      dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
      rowIndex++;
   }
      sheet.AutoSizeColumn(column.Ordinal);
 }

But it doesn’t work. How to do right?

Answer 1

Here is some code that is working for me, using your loops:

    HSSFWorkbook spreadsheet = new HSSFWorkbook();

    DataSet results = GetSalesDataFromDatabase();

    //here, we must insert at least one sheet to the workbook. otherwise, Excel will say 'data lost in file'
    HSSFSheet sheet1 = spreadsheet.CreateSheet("Sheet1");

    foreach (DataColumn column in results.Tables[0].Columns)
    {
        int rowIndex = 0;
        foreach (DataRow row in results.Tables[0].Rows)
        {
            HSSFRow dataRow = sheet1.CreateRow(rowIndex);
            dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
            rowIndex++;
        }
        sheet1.AutoSizeColumn(column.Ordinal);
    }

    //Write the stream data of workbook to the file 'test.xls' in the temporary directory
    FileStream file = new FileStream(Path.Combine(Path.GetTempPath(), "test.xls") , FileMode.Create);
    spreadsheet.Write(file);
    file.Close();

If it doesn’t work for you then we need to look at the kind of data you’re pushing out, see if there’s a difference that makes a difference there. (I’m assuming that we don’t have a version discrepancy or anything like that).