using NPOI.HSSF.UserModel;
using NPOI.HSSF.Util;
using NPOI.DDF;
using NPOI.SS.UserModel;
using System.IO;
using System.Data;

protected void Button2_Click(object sender, EventArgs e)
        {
           //呼叫儲存過程
            SqlConnection conn = new SqlConnection(connectionString);
            conn.Open();
            SqlCommand cmd = new SqlCommand("儲存過程名",conn);
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.Add("@引數1", SqlDbType.VarChar, 50);
            cmd.Parameters.Add("@引數2", SqlDbType.VarChar,50);
      cmd.Parameters["@引數1"].Value = DropDownList1.SelectedValue;
            cmd.Parameters["@引數2"].Value = TextBox1.Text;
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            DataTable dt = ds.Tables[0];
            string excelname = System.DateTime.Now.ToString().Replace(":", "").Replace("-", "").Replace(" ", "");
            string filePath = System.Web.HttpContext.Current.Server.MapPath("ReadExcel") + "\\" + excelname + ".xls";
            MemoryStream ms = RenderDataTableToExcel(dt) as MemoryStream;
            FileStream fs = new FileStream(filePath, FileMode.Create, FileAccess.Write);
            byte[] data = ms.ToArray();
            fs.Write(data, 0, data.Length);
            fs.Flush();
            fs.Close();
            data = null;
            ms = null;
            fs = null;
            Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
            Response.AppendHeader("content-disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(excelname, System.Text.Encoding.UTF8) + ".xls");
            Response.ContentType = "Application/excel";
            Response.WriteFile(filePath);
            Response.End();
           
        }
        public Stream RenderDataTableToExcel(DataTable SourceTable)
        {

            MemoryStream ms = new MemoryStream();
            NPOI.HSSF.UserModel.HSSFWorkbook workbook = new NPOI.HSSF.UserModel.HSSFWorkbook();
            NPOI.SS.UserModel.ISheet sheet = workbook.CreateSheet();
            NPOI.SS.UserModel.IRow headerRow = sheet.CreateRow(0);
            sheet.SetColumnWidth(1, 100);
            headerRow.CreateCell(0).SetCellValue("編號");
            headerRow.CreateCell(1).SetCellValue("圖片");
            int rowIndex = 1;
            foreach (DataRow row in SourceTable.Rows)
            {
                NPOI.SS.UserModel.IRow dataRow = sheet.CreateRow(rowIndex);
                dataRow.Height = 200;
                dataRow.CreateCell(0).SetCellValue(row["id"].ToString());             
                if (row["image"].ToString() != "" )
                {
                    byte[] bytes = System.IO.File.ReadAllBytes(row["image"].ToString());
                    int pictureIdx = workbook.AddPicture(bytes, PictureType.JPEG);
                    HSSFPatriarch patriarch = (HSSFPatriarch)sheet.CreateDrawingPatriarch();
                    HSSFClientAnchor anchor = new HSSFClientAnchor(88, 20, 0, 0, 1, rowIndex, 2, rowIndex + 1);
                    HSSFPicture pict = (HSSFPicture)patriarch.CreatePicture(anchor, pictureIdx);   
                }
                rowIndex++;
            }
            workbook.Write(ms);
            ms.Flush();
            ms.Position = 0;
            sheet = null;
            headerRow = null;
            workbook = null;
            return ms;
        }
 

感謝三位博主的知識分享，在看我的文章之前可以先參考三位博主的文章。