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XlsxFormatProvider.Export value cannot be null parameter workbook

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SpreadProcessing
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Carlos
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Carlos asked on 15 Apr 2019, 01:14 PM

Hello,

When attempting to export a manually created workbook I obtain this error message: 

Value cannot be null.
Parameter name: workbook at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.Utilities.XlsxHelper.ConvertColumnPixelWidthToExcelWidth(Workbook workbook, Double columnWidthInPixels)

   at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.Contexts.XlsxWorksheetExportContext..ctor(XlsxWorkbookExportContext workbookContext, Worksheet worksheet, Int32 sheetNo)
   at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.Contexts.XlsxWorkbookExportContext.InitializeWorksheetContexts()
   at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.Contexts.XlsxWorkbookExportContext.Initialize()
   at Telerik.Windows.Documents.Spreadsheet.FormatProviders.OpenXml.Xlsx.XlsxFormatProvider.ExportOverride(Workbook workbook, Stream output)
   at [Redacted] Controller.cs:line 203

I Generate the workbook using this method:

public Workbook WriteExcelFile(List<Object> list)
        {

            Workbook workbook = new Workbook();
            using (Worksheet worksheet = workbook.Worksheets.Add())
            {
                CellRange range = new CellRange(1, 1, list.Count, 5);
                CellSelection selection = worksheet.Cells[range];

                if (selection.CanInsertOrRemove(range, ShiftType.Right))
                {
                    selection.Insert(InsertShiftType.Right);
                }

                for (int row = 0; row < list.Count; row++)
                {
                    worksheet.Cells[row, 0].SetValue(list[row].string1);
                    worksheet.Cells[row, 1].SetValue(list[row].string2);
                    worksheet.Cells[row, 2].SetValue(list[row].string3);
                    worksheet.Cells[row, 3].SetValue(list[row].string4);
                    worksheet.Cells[row, 4].SetValue(list[row].string5);
               }
            }

            return workbook;
        }

The attempt to write it to a memory stream (FileStream was also attempted)

using (Stream output = new MemoryStream(10000))
      formatProvider.Export(workbook, output);

 

Could you help me understand the reason behind this error?

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Nikolay Demirev
Telerik team
answered on 18 Apr 2019, 06:20 AM
Hi Carlos,

Your code is disposing the worksheet before exporting it. Internally it is setting the workbook of that worksheet to null, and when you try to export it it throws an exception.

Regards,
Nikolay Demirev
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