OpenXML: excel found unreadable content in .xsls - excel

Question

I'm using OpenXML in my ASP.NET application. Here is the code for generating it:
MemoryStream ms = new System.IO.MemoryStream();
SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Create(ms, SpreadsheetDocumentType.Workbook);
WorkbookPart workbookPart = spreadsheetDocument.AddWorkbookPart();
workbookPart.Workbook = new Workbook();
WorksheetPart worksheetPart = workbookPart.AddNewPart<WorksheetPart>();
worksheetPart.Worksheet = new Worksheet();
UInt32Value rowIndex = 0;
SheetData sheetData = new SheetData();
Row r1 = new Row() { RowIndex = rowIndex };
Cell c1 = new Cell() { DataType = CellValues.String, CellValue=new CellValue("col1") };
Cell c2 = new Cell() { DataType = CellValues.String, CellValue = new CellValue("col2") };
Cell c3 = new Cell() { DataType = CellValues.String, CellValue = new CellValue("col3") };
Cell c4 = new Cell() { DataType = CellValues.String, CellValue = new CellValue("col4") };
r1.Append(new List<Cell>() { c1, c2, c3, c4 });
rowIndex++;
sheetData.Append(r1);
foreach (Rezultat rez in rezultati)
{
Row r2 = new Row() { RowIndex = rowIndex };
Cell c1 = new Cell() { DataType = CellValues.String, CellValue = new CellValue(rez.a) };
Cell c2 = new Cell() { DataType = CellValues.String, CellValue = new CellValue(rez.b) };
Cell c3 = new Cell() { DataType = CellValues.String, CellValue = new CellValue(rez.c) };
Cell prolaz = new Cell() { DataType = CellValues.String };
if (rez.d)
{
prolaz.CellValue = new CellValue("DA");
}
else
{
prolaz.CellValue = new CellValue("NE");
}
r2.Append(new List<Cell>() { c1,c2,c3,c4 });
rowIndex++;
sheetData.Append(r2);
}
worksheetPart.Worksheet.Append(sheetData);
Sheets sheets = new Sheets();
Sheet sheet = new Sheet();
sheet.Name = "first";
sheet.SheetId = 1;
sheet.Id = spreadsheetDocument.WorkbookPart.GetIdOfPart(worksheetPart);
sheets.Append(sheet);
spreadsheetDocument.WorkbookPart.Workbook.AppendChild<Sheets>(sheets);
spreadsheetDocument.WorkbookPart.Workbook.Save();
spreadsheetDocument.Close();
string fileName = "testOpenXml.xlsx";
Response.Clear();
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", string.Format("attachment; filename={0}", fileName));
ms.WriteTo(Response.OutputStream);
ms.Close();
Response.End();
When I download it, and try to open it in excel, I got message that excel found unreadable context in excel.I suppose I have to change the way how I geenrate excel. I tried couple of solutions, some gave same error and some open excel, but with no data in it.

Answer 1

You will get this error if the cells do not appear in order in the file.
If you are using Microsoft's Sample Code in "How to: Insert text into a cell in a spreadsheet document (Open XML SDK)" in DevCenter you will see there is a function called InsertCellInWorksheet. This function has the defective line in it:
if (string.Compare(cell.CellReference.Value, cellReference, true) > 0)
If you have more than 26 columns, this will cause them to be sorted like this:
A1 AA1 AB1 B1 C1 D1 E1 ....
The result is you will see the data in column A and from AA on. Columns B through Z will be missing and you will get the dreaded "Excel found unreadable content" message.
You need to replace this string.Compare with a function that will put AA1 after Z1, or... if you know you are creating everything in order change it to if (false).

Answer 2

What you want to create are cells of type InlineString instead of String.
Below is a snippet to achieve part of what you need. Hopefully, you can modify it to your needs.
SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Create(#"test.xlsx", SpreadsheetDocumentType.Workbook);
WorkbookPart workbookPart = spreadsheetDocument.AddWorkbookPart();
WorksheetPart worksheetPart = workbookPart.AddNewPart<WorksheetPart>();
Row row = new Row { RowIndex = 1 };
Cell cell1 = new Cell { DataType = CellValues.InlineString };
InlineString inlineString1 = new InlineString();
Text text = new Text { Text = "col1" };
inlineString1.Append(text);
cell1.Append(inlineString1);
Cell cell2 = new Cell { DataType = CellValues.InlineString };
InlineString inlineString2 = new InlineString();
Text text2 = new Text { Text = "col2" };
inlineString2.Append(text2);
cell2.Append(inlineString2);
row.Append(new List<Cell>() { cell1, cell2 });
SheetData sheetData = new SheetData();
sheetData.Append(row);
Worksheet worksheet = new Worksheet();
worksheet.Append(sheetData);
worksheetPart.Worksheet = worksheet;
worksheetPart.Worksheet.Save();
Sheets sheets = new Sheets();
string relId = workbookPart.GetIdOfPart(worksheetPart);
Sheet sheet = new Sheet { Name = "Sheet1", SheetId = 1, Id = relId };
sheets.Append(sheet);
Workbook workbook = new Workbook();
workbook.Append(sheets);
spreadsheetDocument.WorkbookPart.Workbook = workbook;
spreadsheetDocument.WorkbookPart.Workbook.Save();
spreadsheetDocument.Close();

Answer 3

I know this is an old question, but I ran into this problem and found the solution in a MSDN forum. The SDK samples contain code that simply does not work with columns beyong Z (like AA for example).
As mentioned here, the problem is that using alphabetial order, AA1 will come before B1 and so on. The way to resolve it is to make the letters base-26 numbers. In the very same MSDN forum, the solution was given.
First create a base-26 converter:
//Hexavigesimal (Excel Column Name to Number) - Bijective
private int fromBase26(string colName)
{
colName = colName.ToUpper();
int decimalValue = 0;
for (int i = 0; i < colName.Length; i++)
{
decimalValue *= 26;
decimalValue += (colName[i] - 64);
}
return decimalValue;
}
Then, change this line in the method to insert a cell in the worsheet from:
if (string.Compare(cell.CellReference.Value, cellReference, true) > 0)
To:
if (fromBase26(Regex.Replace(cell.CellReference.Value, #"[\d-]", string.Empty)) > fromBase26(Regex.Replace(cellReference, #"[\d-]", string.Empty)))