ASP.NET 导出Excel文档

 System.IO.TextWriter writer = new System.IO.StreamWriter(Server.MapPath("/provprice.xls"), false, System.Text.Encoding.GetEncoding("utf-8"));
             writer.Write("<table cellspacing=\"3\" style=\"font-family:宋体\" cellpadding=\"5\" rules=\"all\" border=\"1\">");
             writer.WriteLine("<tr style=\"font-weight:bold\"><td>");
             writer.Write("供货商");
             writer.Write("</td><td>");
             writer.Write("商品");
             writer.Write("</td><td>");
             writer.Write("库存");
             writer.Write("</td><td>");
             writer.Write("价格");
             writer.Write("</td><td>");
             writer.Write("开始时间");
             writer.Write("</td><td>");
             writer.Write("结束时间");
             writer.Write("</td>");
             writer.WriteLine("</tr>");
             ///这里搜索要导出的数据信息（DataTable）
             foreach (DataRow dr in dt.Rows)
             {
                 writer.Write("<tr><td>");
                 writer.Write(dr["ProviderName"].ToString());
                 writer.Write("</td><td>");
                 writer.Write(dr["Name"].ToString());
                 writer.Write("</td><td>");
                 writer.Write(dr["Inventory"].ToString());
                 writer.Write("</td><td>");
                 writer.Write(dr["Prices"].ToString());
                 writer.Write("</td><td>");
                 writer.Write(dr["Begin_Time"].ToString());
                 writer.Write("</td><td>");
                 writer.Write(dr["End_Time"].ToString());
                 writer.Write("</td></tr>");
             }
             writer.Write("</table>");
             writer.Close();
             dt = null;