asp.net二种方式生成Excel供下载

   private void Page_Load(object sender, System.EventArgs e)
  {
   ds = new DataSet();
   sqlDataAdapter1.Fill(ds);
   DataGrid1.DataSource = ds;
   DataGrid1.DataBind();
   // 在此处放置用户代码以初始化页面
  } 

public void CreateExcel(DataSet ds,string typeid,string FileName)
  {
   HttpResponse resp;
   resp = Page.Response;
   resp.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
   resp.AppendHeader("Content-Disposition", "attachment;filename=" + FileName);
   string colHeaders= "", ls_item="";
   int i=0;

   //定义表对象与行对像，同时用DataSet对其值进行初始化
   DataTable dt=ds.Tables[0];
   DataRow[] myRow=dt.Select("");
   // typeid=="1"时导出为EXCEL格式文件；typeid=="2"时导出为XML格式文件
   if(typeid=="1")
   {
    //取得数据表各列标题，各标题之间以/t分割，最后一个列标题后加回车符,Tab表示下格,cr表示下一行
    for(i=0;i<dt.Columns.Count;i++)
    {
     colHeaders+=dt.Columns[i].Caption.ToString()+"/t";colHeaders +=dt.Columns[i].Caption.ToString() +"/n";
    }
    //向HTTP输出流中写入取得的数据信息
    resp.Write(colHeaders);
    //逐行处理数据
    foreach(DataRow row in myRow)
    {
     //在当前行中，逐列获得数据，数据之间以/t分割，结束时加回车符/n
     for(i=0;i<row.ItemArray.Length-1;i++)
     {
      ls_item +=row[i].ToString() + "/t";
     }
     ls_item += row[i].ToString() +"/n";
     //当前行数据写入HTTP输出流，并且置空ls_item以便下行数据
     resp.Write(ls_item);
     ls_item="";
    }
   }
   else
   {
    if(typeid=="2")
    {
     //从DataSet中直接导出XML数据并且写到HTTP输出流中
     resp.Write(ds.GetXml());
    }
   }
   //写缓冲区中的数据到HTTP头文件中
   resp.End();
  }

  public void ToExcel(System.Web.UI.Control ctl)
  {
   HttpContext.Current.Response.AppendHeader("Content-Disposition","attachment;filename=Excel.xls");
   HttpContext.Current.Response.Charset ="UTF-8";
   HttpContext.Current.Response.ContentEncoding =System.Text.Encoding.Default;
   HttpContext.Current.Response.ContentType ="application/ms-excel";
   ctl.Page.EnableViewState =false;
   System.IO.StringWriter tw = new System.IO.StringWriter() ;
   System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter (tw);
   ctl.RenderControl(hw);
   HttpContext.Current.Response.Write(tw.ToString());
   HttpContext.Current.Response.End();
   //Response.Redirect(Request.RawUrl);
  }

  private void Button1_Click(object sender, System.EventArgs e)
  {   
   //CreateExcel(ds,"1","test.xml");
   ToExcel(DataGrid1);
  }

 }