Response.Clear();

            Response.BufferOutput = true;

            string style = "<style> td{ mso-number-format:\"\\@\" } </style> ";

            //设定输出的字符集

            Response.Charset = "GB2312";

            //假定导出的文件名为FileName.xls

            Response.AppendHeader("Content-Disposition", "attachment;filename= tiaoma.xls");

            Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");

            //设置导出文件的格式

            Response.ContentType = "application/ms-excel";

            EnableViewState = false;

            System.Globalization.CultureInfo cultureInfo = new System.Globalization.CultureInfo("ZH-CN", true);

            System.IO.StringWriter stringWriter = new System.IO.StringWriter(cultureInfo);

            System.Web.UI.HtmlTextWriter textWriter = new System.Web.UI.HtmlTextWriter(stringWriter);

            GridView gv = new GridView();

            gv.DataSource = Session["table"] as DataTable;

            gv.DataBind();

            gv.RenderControl(textWriter);

            Response.Write(style);

            Response.Write(stringWriter.ToString());

            Response.End();