C# - Excel Number Formatting Issue with International settings

Question

I am trying to write to an Excel 2003 spreadsheet using c# 3.5. However I am unable to get this to function correctly across different country settings. The country settings

Answer 1

This KB article, and a couple of other KB articles it links to, describe some of the localization issues you may hit when automating Excel from .NET.

It may help explain your problem

Answer 2

I haven't run your code, just scanned it...

First potential Problem: You are checking UseSystemSeparators and then setting the DecimalSeparaor and ThousandsSeparator.

        if (app.UseSystemSeparators == false)
        {
            app.DecimalSeparator = ci.NumberFormat.NumberDecimalSeparator;
            app.ThousandsSeparator = ci.NumberFormat.NumberGroupSeparator;
        }

Then right after, you are turning on SystemSeparators, so the code above is not doing anything since you are turning the system seperators on.

        app.UseSystemSeparators = true;

Second potential problem/suggestion: When setting the cell value, set it as a double value instead of string, let Excel format the number for you.

Answer 3

Thanks to Chris and Joe, I finally got the code to work as desired.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Microsoft.Office.Interop.Excel;
using System.Runtime.InteropServices;
using System.Threading; 
using System.Globalization;


namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public void ExportDTToExcel()
        {

            Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();
            app.Visible = true;

            string culture = System.Threading.Thread.CurrentThread.CurrentCulture.ToString();//"en-GB";
            CultureInfo ci = new CultureInfo(culture);

            bool systemseparators = app.UseSystemSeparators  ;
            if (app.UseSystemSeparators == false)
            {

                app.UseSystemSeparators = true;

            }

            // Content.   
            Workbook wb = app.Workbooks.Add(XlWBATemplate.xlWBATWorksheet);
            Worksheet ws = (Worksheet)wb.ActiveSheet;            
            try
            {
                SetCellValue("3706888.0300", ws, 0, 0, ci);
                SetCellValue("2587033.8000", ws, 1, 0, ci);
                SetCellValue("2081071.1800", ws, 2, 0, ci);
                SetCellValue("9030160.3333", ws, 3, 0, ci);
                SetCellValue("42470.9842", ws, 4, 0, ci);
                SetCellValue("4465546.2800", ws, 5, 0, ci);
                SetCellValue("1436037.3200", ws, 6, 0, ci);
                SetCellValue("111650.0000", ws, 7, 0, ci);
                SetCellValue("2567007.0833", ws, 8, 0, ci);

            }
            catch (Exception e)
            {


                    MessageBox.Show(e.Message);

            }

            app.UseSystemSeparators = systemseparators;
            Marshal.ReleaseComObject(app);
            Marshal.ReleaseComObject(wb);
            Marshal.ReleaseComObject(ws);
            app = null;
            wb = null;
            ws = null;
        }

        private static void SetCellValue(string data, Worksheet ws,int row, int col, CultureInfo ci)
        {
                double val;
                try
                {
                    val = Convert.ToDouble(data);
                    Console.WriteLine(val);
                }
                catch (Exception e)
                {

                    //Util.Log("Null Value ignored.", LogType.ERROR);
                    return;
                }

                try
                {
                    string s = val.ToString();
                    ws.Cells[row + 2 , col + 1] = s;

                    //Util.Log("S:" + s, LogType.ERROR);
                }
                catch
                {
                    //Util.Log("Null Value ignored.", LogType.ERROR);
                }
            }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Cursor = Cursors.WaitCursor;
            ExportDTToExcel();
            this.Cursor = Cursors.Default;
        }


    }
}

Answer 4

Excel used over COM has several restrictions most important ones to respect are:

• Use the en-US culture (LCID bug)
• Call all the methods from one and the same Thread (set to the right culture "en-US")

Then you'll get rid of most sporadic crashes regarding Excel automation & localization.