NPOI: Excel column formatted to decimal with SXSSFWorkbook? - asp.net

Question

I am developing a website with ASP.net (VS2015 C #).
I need to export a MySql table with a large amount of data (500000+ rows and 100 columns) to excel (xlsx), with format.
After trying many options, the NPOI (v 3.20) library allows this export using types that use streaming (SXSSFWorkbook & SXSSFSheet).
If I use XSSFWorkbook I get and Out of memory filling the rows.
With SXSSFWorkbook I have been able to format the xlsx with different fonts and colors, but I am having problems with the types of data exported:
Date types ok
Int types ok
Text ok
Decimals inputs like 100.35 --> problems, I get a text column. I need a ouput like a number 100,35.
The code I use to format the data is:
SXSSFWorkbook wb = new SXSSFWorkbook();
SXSSFSheet sh = (SXSSFSheet)wb.CreateSheet("Sheet 1");
sh.SetRandomAccessWindowSize(100);
ICellStyle testStyleHeader = wb.CreateCellStyle();
ICellStyle testStyleRow = wb.CreateCellStyle();
// Header Style
testStyleHeader.FillForegroundColor = NPOI.SS.UserModel.IndexedColors.RoyalBlue.Index;
testStyleHeader.FillPattern = FillPattern.SolidForeground;
// Double style (with 2 decimals like 453.65)
ICellStyle cellStyleDouble = wb.CreateCellStyle();
cellStyleDouble.DataFormat = wb.CreateDataFormat().GetFormat("0.00");
// Font
XSSFFont hFontBlack = (XSSFFont)wb.CreateFont();
hFontBlack.FontHeightInPoints = 11;
hFontBlack.FontName = "Calibri";
hFontBlack.Color = NPOI.SS.UserModel.IndexedColors.Black.Index;
testStyleHeader.SetFont(hFontBlack);
IRow row = sh.CreateRow(0);
int j = 0;
ICell cell = row.CreateCell(j);
// Fill Header row
cell.SetCellValue("XXXX"); cell.CellStyle = testeStyleHeader; j++; cell = row.CreateCell(j);
cell.SetCellValue("YYYY"); cell.CellStyle = testeStyleHeader; j++; cell = row.CreateCell(j);
cell.SetCellValue("ZZZZ"); cell.CellStyle = testeStyleHeader; j++; cell = row.CreateCell(j);
cell.SetCellValue("WWWW"); cell.CellStyle = testeStyleHeader; j++; cell = row.CreateCell(j);
// Fill Rows
int i = 1; // row Number
IRow row2; // No Header Row
ICell cell2; // No Header cell
while (dr.Read()) // dr is the DataReader
{
row2 = sh.CreateRow(i);
for (int cont = 0; cont < NumColumns; cont++)
{
if (cont == 0) // This column is a date
{
…. // code for date format
}
else if (cont == 3) // Double column with 2 decimals¡! (values samples 100.45 5654.80 etc.)
{
ICell cell3 = row2.CreateCell(j, NPOI.SS.UserModel.CellType.Numeric);
cell3.CellStyle = cellStyleDouble;
cell3.SetCellValue(Convert.ToDouble(dr[cont]));
}
else
{…. // code for tex format, int format etc.
}
}
i++;
}
With this code, in the decimal column (cont ==3), I get a text column.
However, with the same code, if I declare the no streaming types:
XSSFWorkbook wb = new XSSFWorkbook();
XSSFSheet sh = (SSFSheet)wb.CreateSheet("Sheet 1");
Only with this changes I get a perfect numeric columnn 3...
For this line:
cellStyleDouble.DataFormat = wb.CreateDataFormat().GetFormat("0.00");
I have tried with different types:
"#.#"
"#,##0.000"
"##.#"
Etc…
In some cases I get a number, but not with the desired format.
So...streaming types do not allow this formatting?

Answer 1

Just change the Culture Info to en-US
Thread.CurrentThread.CurrentCulture = new CultureInfo("en-Us");
ISheet worksheet = Workbook.CreateSheet(dt.TableName);
IRow HeaderRow = worksheet.CreateRow(0);
for (int i = 0; i < dt.Columns.Count; i++)
{
ICell HeaderCell = HeaderRow.CreateCell(i);
HeaderCell.SetCellValue(dt.Columns[i].ColumnName);
}
for (int j = 0; j < dt.Rows.Count; j++)
{
IRow Row = worksheet.CreateRow(j + 1);
for (int i = 0; i < dt.Columns.Count; i++)
{
ICell Cell = Row.CreateCell(i);
if (dt.Columns[i].DataType.IsOfType(typeof(decimal)) && dt.Rows[j][i] != DBNull.Value)
{
Cell.SetCellType(CellType.Numeric);
Cell.SetCellValue((double)dt.Rows[j][i]);
}
else
Cell.SetCellValue(dt.Rows[j][i].ToString());
}
}
Thread.CurrentThread.CurrentCulture = new CultureInfo("pt-Br");
It works for me!

Answer 2

can you try your formatting based on below code snippet. I am using this approach to format phone number.
XSSFCellStyle currencyCellStyle = (XSSFCellStyle)workbook.CreateCellStyle();
XSSFDataFormat currencyDataFormat = (XSSFDataFormat)workbook.CreateDataFormat();
currrencyCellStyle.SetDataFormat(currencyDataFormat.GetFormat("00000.00")); //Formats: #####.##, 00000##.##
sometimes its tricky to find exact formatting in NPOI :). Please try below approaches
ICellStyle CellStyle = workbook.CreateCellStyle();
CellStyle.DataFormat = workbook.CreateDataFormat().GetFormat("number"); // or Number
or
CellStyle cellStyle = wb.createCellStyle();
cellStyle.setDataFormat(wb.getCreationHelper().createDataFormat().getFormat("#.#")); // or #####.## or number