Format an Excel column (or cell) as Text in C#?

Question

I am losing the leading zeros when I copy values from a datatable to an Excel sheet. That's because probably Excel treats the values as a number instead of text.

I am copying the values like so:

myWorksheet.Cells[i + 2, j] = dtCustomers.Rows[i][j - 1].ToString();

How do I format a whole column or each cell as Text?

A related question, how to cast myWorksheet.Cells[i + 2, j] to show a style property in Intellisense?

Answer 1

Below is some code to format columns A and C as text in SpreadsheetGear for .NET which has an API which is similar to Excel - except for the fact that SpreadsheetGear is frequently more strongly typed. It should not be too hard to figure out how to convert this to work with Excel / COM:

IWorkbook workbook = Factory.GetWorkbook();
IRange cells = workbook.Worksheets[0].Cells;
// Format column A as text.
cells["A:A"].NumberFormat = "@";
// Set A2 to text with a leading '0'.
cells["A2"].Value = "01234567890123456789";
// Format column C as text (SpreadsheetGear uses 0 based indexes - Excel uses 1 based indexes).
cells[0, 2].EntireColumn.NumberFormat = "@";
// Set C3 to text with a leading '0'.
cells[2, 2].Value = "01234567890123456789";
workbook.SaveAs(@"c:\tmp\TextFormat.xlsx", FileFormat.OpenXMLWorkbook);

Disclaimer: I own SpreadsheetGear LLC