this.dg.Columns[3].Visible = false;
HttpContext.Current.Response.Charset = "GB2312";
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode("out.xls", System.Text.Encoding.UTF8));
HttpContext.Current.Response.ContentType = "application/ms-excel";
this.EnableViewState = false;
System.IO.StringWriter tw;
tw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter hw;
hw = new HtmlTextWriter(tw);
this.dg.RenderControl(hw);
HttpContext.Current.Response.Write(tw.ToString());
HttpContext.Current.Response.End();
this.dg.Columns[3].Visible = true;