// GridView1.AllowPaging = false;//取消分页,使GridView显示全部数据.
       // GridView1.DataBind();//重新绑定.如果不注释这两行,导不出数据,如果注释了这两行,连分页都导出来了,
       //只能导出一个页面的数据
        Response.Clear();
        Response.Charset = "GB2312";
        Response.AppendHeader("Content-Disposition", "attachment;filename= " + Server.UrlEncode("导出.xls"));
        Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");
        Response.ContentType = "application/ms-excel";//设置输出文件类型为excel文件.
        this.EnableViewState = false;
        System.Globalization.CultureInfo myCItrad = new System.Globalization.CultureInfo("ZH-CN", true);
        System.IO.StringWriter stringWrite = new System.IO.StringWriter(myCItrad);
        System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
        GridView1.RenderControl(htmlWrite);
        Response.Write(stringWrite.ToString());
        Response.End();
        GridView1.AllowPaging = true;
        GridView1.DataBind();//重新绑定.