//创建excel
public static string ExportJbnt2Excel(string Exceltitle, string area)
        {
            //创建工作薄  
            HSSFWorkbook wk = new HSSFWorkbook();
            //创建一个名称为Sheet1的表  
            ISheet tb = wk.CreateSheet();
            wk.SetSheetName(0,"Sheet1");
            for (int i = 0; i < 2; i++)
            {
                ICellStyle cellStyle = SetCellStyle(wk, i);
                IRow row = tb.CreateRow(i);
                for (int j = 0; j < 6; j++)
                {
                    ICell cell = row.CreateCell(j);
                    cell.CellStyle = cellStyle;
                }

            }

            MergeCell(tb, tb.GetRow(0).GetCell(2), 0, 0, 2, 5, Exceltitle);
            MergeCell(tb, tb.GetRow(1).GetCell(0), 1, 1, 0, 3, "基本农田占用总面积");
            MergeCell(tb,tb.GetRow(1).GetCell(4),1,1,4,5,area);

            MemoryStream mstream = new MemoryStream();
            wk.Write(mstream);
            DownloadFile(mstream, Exceltitle);
            return null;
        }

   //在客户端保存或查看用流生成的excel文件
public static string DownloadFile(MemoryStream fs, string filename)//必须为FileStream或MemoryStream ，如果用Stream则生成的excel无法正常打开{ 
string fileName = filename+".xls";//客户端保存的文件名 //以字符流的形式下载文件 
byte[] bytes = fs.ToArray(); fs.Read(bytes, 0, bytes.Length); fs.Close(); 
System.Web.HttpContext.Current.Response.Clear(); 

System.Web.HttpContext.Current.Response.ClearContent(); 
System.Web.HttpContext.Current.Response.ClearHeaders(); 
System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream"; 

//通知浏览器下载文件而不是打开  
System.Web.HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)); 
System.Web.HttpContext.Current.Response.AddHeader("Content-Transfer-Encoding", "binary"); System.Web.HttpContext.Current.Response.BinaryWrite(bytes);
 System.Web.HttpContext.Current.Response.Flush(); 
System.Web.HttpContext.Current.Response.End();
return null; }