ASP.NET2.0 gridview实现打印和打印预览和导出Excel不出现乱码

protected void btnExcel_Click(object sender, EventArgs e)
    {
        Response.Clear();
        Response.Buffer = true;
        Response.AddHeader("content-disposition", "attachment;filename=FileName.xls");
        Response.Charset = "gb2312";
        // 如果设置为 GetEncoding("GB2312");导出的文件将会出现乱码！！！
        Response.ContentEncoding = System.Text.Encoding.UTF7;
        Response.ContentType = "application/vnd.xls";
         stringWrite = new ();
        System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);
        GridView1.AllowPaging = false;
        bind();
        GridView1.RenderControl(htmlWrite);
        Response.Write(stringWrite.ToString());
        Response.Flush();
        Response.End();
        GridView1.AllowPaging = true;
        bind();
    }
    public override void VerifyRenderingInServerForm(Control control)
    {
    }
    protected override void Render(HtmlTextWriter writer)
    {
        if (Page != null)
        {
            Page.VerifyRenderingInServerForm(this);
        }
        base.Render(writer);
    }
 protected void btnPrint_Click(object sender, EventArgs e)
    {
        Response.Write("<script> window.print()</script>");
    }
}
这是在网上找到原代码，用上之后导出Excel有时候还是有乱码出现。打印的时候也把整个的网页全打出来了，我只需要把Gridview的内容打出来，该怎么改代码啊？哪位帮忙分析下或者贴个代码出来，谢谢了…………