在以下按钮单击事件中实现：
private void btnMIME_Click(object sender, System.EventArgs e)
{
 BindData();
 Response.ContentType = "application/vnd.ms-excel";
 Response.AddHeader("Content-Disposition", "inline;filename="
   +   HttpUtility.UrlEncode("下载文件.xls",Encoding.UTF8   )   );  
 

 //如果输出为Word，修改为以下代码
 //Response.ContentType = "application/ms-word"
 //Response.AddHeader("Content-Disposition", "inline;filename=test.doc")
 StringBuilder sb=new StringBuilder();
 System.IO.StringWriter sw = new System.IO.StringWriter(sb);
 System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(sw);
 sb.Append("<html><body>");
 dgShow.RenderControl(hw);
 sb.Append("</body></html>");
 Response.Write(sb.ToString());
 Response.End();
}
注：1.若DataGrid中有按钮列，则在导出前应先将其隐藏.
    2.若DataGrid有分页，而又要打印所有数据的话就应先取消分页.