datagrid 导出excel 将datagrid控件内容输出到excel文件

if (eformsn.Text=="")
{
DataGrid1.Visible=false;
Label1.Text="要汇入EXCEL，请先输入申请单号!";
Label1.Visible=true;
}
else
{
dl.DataSource=DB("query", "select * from msi_eol_list_line where eformsn="+eformsn.Text+" order by eformsn").Tables[0].DefaultView;
dl.DataBind();

//下面这行很重要，attachment 参数表示作为附件下载，您可以改成online在线打开
//filename=FileFlow.xls 指定输出文件的名称，注意其扩展名和指定文件类型相符，可以为：.doc .xls .txt .htm　　

Response.AppendHeader("Content-Disposition","attachment;filename=EOL_"+eformsn.Text+".xls");
Response.ContentEncoding=System.Text.Encoding.GetEncoding("utf-8");　

//Response.ContentType指定文件类型 可以为application/ms-excel,application/ms-word ,application/ms-txt,application/ms-html或其他浏览器可直接支持文档　
Response.ContentType = "application/ms-excel";
dl.EnableViewState = false;　

System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);

//将目标数据绑定到输入流输出　　
//this 表示输出本页，你也可以绑定datagrid,或其他支持obj.RenderControl()属性的控件　　
dl.RenderControl(oHtmlTextWriter);
//this.DataBind.RenderControl(oHtmlTextWriter);
Response.Write(oStringWriter.ToString());
Response.End();
}
}