asp.net导出Excel显示中文乱码的解决方法

代码如下:
  protected void btnExcel_Click(object sender, EventArgs e)
    {
        List<bUFlow.Model.orderhistory> orderlist = dal.GetOrderList2("");
        string filename = "3g流量网龄升级计划用户表";
        string name1 = filename;
        string bname = Common.MyRequest.GetBrowserName().ToLower();
        if (bname.Contains("firefox"))
        {
        }
        else if (bname.Contains("ie"))
        {
            filename = HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8);
        }
        else
        {
            filename = HttpUtility.UrlEncode(filename, System.Text.Encoding.UTF8);
        }

        HttpResponse resp = System.Web.HttpContext.Current.Response;
        resp.Charset = "utf-8";
        resp.Clear();
        resp.AppendHeader("Content-Disposition", "attachment;filename=" + filename + ".xls");
        resp.ContentEncoding = System.Text.Encoding.UTF8;

        resp.ContentType = "application/ms-excel";
        string style ="<meta http-equiv=/"content-type/" content=/"application/ms-excel; charset=utf-8/"/>"+ "<style> .table{ font: 9pt Tahoma, Verdana; color: #000000; text-align:center;  background-color:#8ECBE8;  }.table td{text-align:center;height:21px;background-color:#EFF6FF;}.table th{ font: 9pt Tahoma, Verdana; color: #000000; font-weight: bold; background-color: #8ECBEA; height:25px;  text-align:center; padding-left:10px;}</style>";
        resp.Write(style);
        //resp.Write(ExportTable(list));
        resp.Write("<table class='table'><tr><th>" +"手机"+ "</th><th>" + "渠道" + "</th><th>" +"时间" + "</th></tr>");
        //dbVideoList = (List<subShiyongModel>)Session["dbVideoList"];
        foreach (bUFlow.Model.orderhistory model in orderlist)
        {
            resp.Write("<tr><td>" + model.phone + "</td>");