How to AutoFit excel column using OpenXML Package

Question

This code to generate Excel spreadsheet Using openxml package. Please anyone tell how to auto fit its column width.

OpenXmlPackage.SpreadsheetDocument spreadsheetDocument = OpenXmlPackage.SpreadsheetDocument.Create(downloadFilePath, OpenXml.SpreadsheetDocumentType.Workbook);
// Add a WorkbookPart to the document.
OpenXmlPackage.WorkbookPart workbookpart = spreadsheetDocument.AddWorkbookPart();
// Add a WorksheetPart to the WorkbookPart.
workbookpart.Workbook = new OpenXmlSpreadsheet.Workbook();
int numDates = datesObject.Length;

// Add Sheets to the Workbook.
OpenXmlSpreadsheet.Sheets sheets = new OpenXmlSpreadsheet.Sheets();
OpenXml.UInt32Value sheetId = 1;

OpenXmlPackage.WorksheetPart firstWorksheetPart = workbookpart.AddNewPart<OpenXmlPackage.WorksheetPart>();
firstWorksheetPart.Worksheet = new OpenXmlSpreadsheet.Worksheet(new OpenXmlSpreadsheet.SheetData());
// Append a new worksheet and associate it with the workbook.
OpenXmlSpreadsheet.Sheet firstSheet = new OpenXmlSpreadsheet.Sheet() { Id = spreadsheetDocument.WorkbookPart.GetIdOfPart(firstWorksheetPart), SheetId = sheetId, Name = "Summary" };
sheets.Append(firstSheet);
sheetId++;

 OpenXmlSpreadsheet.SheetData firstSheetData = firstWorksheetPart.Worksheet.GetFirstChild<OpenXmlSpreadsheet.SheetData>();

 DataTable summaryTable = new DataTable();
 summaryTable.Clear();
 summaryTable.Columns.Add("name");
 summaryTable.Columns.Add("value");

 DataRow _summaryInfo = summaryTable.NewRow();
 _summaryInfo["name"] = "Clinic Name";
 _summaryInfo["value"] = userInfo[0];
 summaryTable.Rows.Add(_summaryInfo);



 int firstRowCount = summaryTable.Rows.Count;

 for (int rowNumber = 1; rowNumber <= firstRowCount; rowNumber++)
 {
      DataRow dataRow = summaryTable.Rows[rowNumber - 1];
      OpenXmlSpreadsheet.Row contentRow = ExcelHandler.createContentRow(dataRow, rowNumber);
      firstSheetData.AppendChild(contentRow);
 }

 firstWorksheetPart.Worksheet.Save();

Answer 1

The auto-fit logic is something which is implemented by Microsoft Excel, and is not a part of the OpenXML spreadsheet format. Auto-fit involves measuring the width (or height) of the value in each cell and finding the maximum value.

In order to implement auto-fit in your own code, you will have to manually measure the text; you can use TextRenderer.MeasureText or Graphics.MeasureString with appropriate format flags (disable prefix characters). This will give you a size in pixels, which you will need to convert to Excel's convoluted column width units. The formula for this is:

width = Truncate([{Number of Characters} * {Maximum Digit Width} + {5 pixel padding}]/{Maximum Digit Width}*256)/256

Taken from this article: Column Class (DocumentFormat.OpenXml.Spreadsheet)

(Maximum Digit Width can be determined by measuring the width of the '0' character using the workbook's default font - told you it was convoluted!)

Once you have obtained the cell widths using this formula, you can find the maximum value and apply it to the Column.Width property.

There are subtle differences in the way Microsoft Excel renders text (compared to how GDI/GDI+ does it), so this method is not 100% accurate - but it is sufficient for most purposes and you can always add some extra padding to ensure a proper fit.