How to set certain column types in Microsoft.Office.Interop.Excel in C#?

Hi @Nicholas Piazza , Welcome to Microsoft Q&A,

It's true that you can't set it to currency format directly, but you can use numberformat to manually set the column's number format to achieve the same effect.

The following are official related links:

https://learn.microsoft.com/en-us/office/vba/api/excel.range.numberformat

Similar code is:：

using Excel = Microsoft.Office.Interop.Excel;

class Program
{
    static void Main(string[] args)
    {
        // Create a new Excel application
        Excel.Application excelApp = new Excel.Application();
        excelApp.Visible = true; // Make Excel visible

        // Add a new workbook
        Excel.Workbook workbook = excelApp.Workbooks.Add();

        // Get the first worksheet
        Excel.Worksheet worksheet = (Excel.Worksheet)workbook.Worksheets[1];

        // Set the data type of the entire column to Currency
        Excel.Range column = worksheet.Columns["A"];
        column.NumberFormat = "$#,##0.00";

        // Example data
        worksheet.Cells[1, 1].Value = "Currency Column";
        worksheet.Cells[2, 1].Value = 1000.50;
        worksheet.Cells[3, 1].Value = 2000.75;
        worksheet.Cells[4, 1].Value = 3000.25;

        // Save the workbook (optional)
        workbook.SaveAs("example.xlsx");

        // Clean up
        workbook.Close();
        excelApp.Quit();
        System.Runtime.InteropServices.Marshal.ReleaseComObject(excelApp);
    }
}

Best Regards,

Jiale

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