Gridview导出为Excel的时候，中文文件名乱码，解决方案（亲测）

        //清除客户端当前显示
        Response.Clear();
        Response.Buffer = true;
        Response.Charset = "GB2312";
        //显示标头
        Response.AddHeader("Content-Disposition", "attachment;   filename=" + System.Web.HttpUtility.UrlEncode("文件名", System.Text.Encoding.UTF8) + ".xls");//这样的话，可以设置文件名为中文，且文件名不会乱码。其实就是将汉字转换成UTF8
        Response.ContentEncoding = System.Text.Encoding.UTF7;
        // 如果设置为 GetEncoding("GB2312");导出的文件将会出现乱码！

        Response.ContentType = "application/ms-excel";//设置输出文件类型为excel文件。    

        System.IO.StringWriter stringWrite = new System.IO.StringWriter();

        HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);

        GridView1.RenderControl(htmlWrite);
        Response.Write(stringWrite.ToString());
        Response.End();