asp.net导出数据生成真正的excel文件

asp.net导出数据生成excel文件，如果修改了生成的excel文件它会生成其它几个文件，例如怎样防止啊

我一般都是用gridview导出数据，你看看代码吧 对你有没有帮助， ----------------------按钮事件-------------------protected void Button2_Click(object sender, EventArgs e)
{
Export("application/ms-excel", "sssss.xls");
} private void Export(string FileType, string FileName)
{
Response.Charset = "GB2312";
Response.ContentEncoding = System.Text.Encoding.UTF7;
Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName, Encoding.UTF8).ToString());
Response.ContentType = FileType;
this.EnableViewState = false;
StringWriter tw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(tw);
// turn off paging
GridView1.AllowPaging = false;
this.GridView1.DataBind(); GridView1.RenderControl(hw);
Response.Write(tw.ToString());
Response.End(); // turn the paging on again
GridView1.AllowPaging = true;
this.GridView1.DataBind(); } 下面这句不加的话回出错误 public override void VerifyRenderingInServerForm(Control control)
{ }页面：EnableEventValidation = "false"

由dataset生成  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  for(i=0;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 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();  }