Response.Write中文乱码问题

        public void ExportRuntimeByRobot(DataTable dt, string FileName)
        {
            System.IO.StringWriter sw = new System.IO.StringWriter();
            System.Web.UI.HtmlTextWriter htw = new System.Web.UI.HtmlTextWriter(sw);
            System.Web.UI.WebControls.GridView dg = new System.Web.UI.WebControls.GridView();
            DataTable dt2 = new DataTable();
            string strContent = "";
            try
            {
                Response.Clear();
                Response.AddHeader("content-disposition", "attachment; filename=" + FileName + ".xls");
                Response.ContentType = "application/vnd.ms-excel";
                Response.Charset = "";
                HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.Default;


                dg.Attributes.Add("style", "vnd.ms-excel.numberformat:@");
                dg.DataSource = dt;
                dg.DataBind();
                dg.RenderControl(htw);
                Response.Write(sw.ToString());
                Response.End();
            }
            catch (Exception ex)
            {

            }
            finally
            {
                strContent = null;
            }
        }