using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Excel=Microsoft.Office.Interop.Excel;
using System.IO;

namespace MSOInterop
{
    public class MSOExcel
    {

        object nothing = Type.Missing;
        object trueValue = true;
        object falseValue = false;
        Excel.Application app;

        private void OpenWorkBook(string fileName)
        {
            try
            {
                app.Workbooks.Open(fileName    // FileName 
                                        , nothing   // UpdateLinks 
                                        , nothing   // ReadOnly 
                                        , nothing   // Format 
                                        , nothing   // Password 
                                        , nothing   // WriteResPassword 
                                        , nothing   // IgnoreReadOnlyRecommended 
                                        , nothing   // Origin 
                                        , nothing   // Delimiter 
                                        , nothing   // Editable 
                                        , nothing   // Notify
                                        , nothing   // Converter 
                                        , nothing   // AddToMRU
                                        );
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
        }

        public MSOExcel(string fileName, bool isVisible)
        {
            try
            {
                app = new Excel.Application();
                app.Visible = isVisible;
                OpenWorkBook(fileName);
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
        }
 public void SetValue(object sheet,object cell,object value)
        {
            Excel.Worksheet ws = app.Workbooks[1].Sheets[sheet];
            Excel.Range rg = ws.get_Range(cell);
            rg.Value2 = value;
        }
       
        public byte[] GetPDF(string fileName)
        {
            app.Workbooks[1].ExportAsFixedFormat(Excel.XlFixedFormatType.xlTypePDF
                                               , fileName
                                               , Excel.XlFixedFormatQuality.xlQualityMinimum);
            app.Workbooks[1].Close(false);
            ((Excel._Application)app).Quit();
            return null;
        }

MSOExcel excel=new MSOExcel(Server.MapPath("~/Templates/WO.xlsx"),false);