...

                DataSet ds1 = Member.GetMembers();//获取要导出的数据

                context.Response.Clear();
                context.Response.Charset = "";
                context.Response.ContentType = "application/vnd.ms-xls";
                StringWriter stringWrite = new StringWriter();
                HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);

                DataGrid dg = new DataGrid();
                dg.DataSource = ds1;
                dg.DataBind();
                dg.RenderControl(htmlWrite);
                context.Response.AddHeader("content-disposition", "attachment;filename=" + HttpUtility.UrlEncode("abcdefg.xls"));
                context.Response.Write(stringWrite.ToString());
                context.Response.End();