Create an Excel file programmatically

using System;

//This is created from the interop tlbimp tool.
// 1) open a .NET cmd box (see the Visual Studio .Net Tools menu)
// 2) find the Excel9.olb file in your Excel program directory 
// 3) copy excel9.olb to your project directory
// 4) cd to your project directory and run 'TlbImp Excel9.olb Excel.dll'
// 5) add excel.dll to the references
 
using Excel;
using System.Reflection; // For Missing.Value and BindingFlags
using System.Runtime.InteropServices; // For COMException

namespace csharp
{
  /// <summary>
  /// Summary description for createexcel.
  /// </summary>
  public class createexcel
  {
    public createexcel()
    {
      ExcelHandler xl = new ExcelHandler();

      xl.Create();

      xl.SetCell("A1", "Title1 - really really long title that is too long");
      xl.SetCell("B1", "Title2 - really really long title that is too long");
      xl.SetCell("C1", "Title3");

      xl.SetBold("A1");
      xl.SetWrapText("A1");
      xl.SetBold("B1");
      xl.SetWrapText("B1");
      xl.SetColumnWidth("B1", 30);
      xl.SetBold("C1");

      xl.SetCell("A2", 2);
      xl.SetCell("B2", 3.2);  //floats are ok
      xl.SetCell("C2", 1);
      xl.SetCell("D2", "@sum(A2:C2)"); // formulas are just strings...
      xl.Save(@"x.xls");

      xl.Quit();
    }
  }

  //does the actual work
  public class ExcelHandler
  {
    Excel.Application exc;
    _Workbook workbook;
    _Worksheet worksheet;
    
    public void Quit()
    {
      exc.Quit();
    }
    public void Save(string fname)
    {
      exc.AlertBeforeOverwriting = true;
      workbook.SaveAs(fname, Excel.XlFileFormat.xlWorkbookNormal, null, null, null, null, Excel.XlSaveAsAccessMode.xlExclusive, null, null, null, null);
    }
    public void Create()
    {
      exc = new Excel.Application();
      if (exc == null) 
      {
        Console.WriteLine("ERROR: EXCEL couldn't be started");
        return;
      }
      exc.Visible = true;

      Workbooks workbooks = exc.Workbooks;
      workbook = workbooks.Add(XlWBATemplate.xlWBATWorksheet);

      Sheets sheets = workbook.Worksheets;
      worksheet = (_Worksheet) sheets.get_Item(1);
      if (worksheet == null) 
      {
        Console.WriteLine ("ERROR in worksheet == null");
      }
    }

    public void SetCell(string address, object val)
    {
      Range range1 = worksheet.get_Range(address, Missing.Value);
      if (range1 == null) 
      {
        Console.WriteLine ("ERROR: range == null");
      }
      Object[] args1 = new Object[1];
      args1[0] = val;
      range1.GetType().InvokeMember("Value", BindingFlags.SetProperty, null, range1, args1);

    }
    public void SetBold(string address)
    {
      Range range1 = worksheet.get_Range(address, Missing.Value);
      if (range1 == null) 
      {
        Console.WriteLine ("ERROR: range == null");
      }
      range1.Font.Bold = true; 
    }
    public void SetWrapText(string address)
    {
      Range range1 = worksheet.get_Range(address, Missing.Value);
      if (range1 == null) 
      {
        Console.WriteLine ("ERROR: range == null");
      }

      range1.WrapText = true; 
    }
    public void SetColumnWidth(string address, int width)
    {
      Range range1 = worksheet.get_Range(address, Missing.Value);
      if (range1 == null) 
      {
        Console.WriteLine ("ERROR: range == null");
      }

      range1.ColumnWidth = width; 
    }
  }
}