导出excel

  public static  void  NPOIExportReport(  string [] titlearry, string  fileurl,DataTable dt)
        {
            FileStream fileStream = null;
            HSSFWorkbook workbook = new HSSFWorkbook();
            ISheet sheet = workbook.CreateSheet("sheet1");
            try
            {
                    sheet = workbook.GetSheetAt(0);
                    IRow row1 = sheet.CreateRow(0);

                    //表头
                    for (int m= 0; m< dt.Columns.Count; m++)
                    {
                        ICell cell = row1.CreateCell(m);
                        cell.SetCellValue(titlearry[m]);
                    }

                    for (int i=0;i<dt.Rows.Count;i++)
                    {
                        IRow row = sheet.CreateRow(i + 1);
                        for(int t = 0; t < dt.Columns.Count; t++)
                           {
                            ICell cell = row.CreateCell(t);
                            cell.SetCellValue(dt.Rows[i][t].ToString());
                            }
                    }

                    fileStream = System.IO.File.Create(fileurl);
                    workbook.Write(fileStream);
                    fileStream.Close();
                    downloadfile(fileurl);
            }
            catch (Exception  ex)
            {
                throw new Exception(ex.Message);
            }
            finally
            {
                if (workbook != null)
                    workbook.Close();
            }
            

        /// <summary>
        /// http页面包头
        /// </summary>
        public static void downloadfile(string s_path)
        {
            System.IO.FileInfo file = new System.IO.FileInfo(s_path);
            HttpContext.Current.Response.ContentType = "application/ms-download";
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.AddHeader("Content-Type", "application/octet-stream");
            HttpContext.Current.Response.Charset = "utf-8";
            HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(file.Name, System.Text.Encoding.UTF8));
            HttpContext.Current.Response.AddHeader("Content-Length", file.Length.ToString());
            HttpContext.Current.Response.WriteFile(file.FullName);
            HttpContext.Current.Response.Flush();
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.End();
        }