protected void Page_Load(object sender, EventArgs e)
 {
     if (Session["Id"] != null)
     {
         Auxiliar aux = new Auxiliar();
         HistoricoVentas hv = new HistoricoVentas();
         string jsonVentas = "";
         Historico serv = new Historico();
         serv.Url = new Juddi().getServiceUrl("Historico");
         jsonVentas = serv.devolverTodo((int)Session["Id"]);
         var javaScriptSerializer = new JavaScriptSerializer();
         hv = javaScriptSerializer.Deserialize<HistoricoVentas>(jsonVentas);
         DataTable dt = new DataTable();
         dt.Columns.AddRange(new DataColumn[4] {
                 new DataColumn("id", typeof(int)),
                                 new DataColumn("tipo", typeof(string)),
                                 new DataColumn("estado",typeof(string)),
                                 new DataColumn("precioventa",typeof(int))
             });
         for (int i = 0; i < hv.ListaVentas.Count; i++)
         {
             dt.Rows.Add(hv.ListaVentas[i].id, hv.ListaVentas[i].tipo, hv.ListaVentas[i].estado, hv.ListaVentas[i].precio);
         }
         GridView1.DataSource = dt;
         GridView1.DataBind();
     }
     else
     {
         Response.Redirect("/");
     }
 }
        public void actualizarVentas()
        {
            this.Dispatcher.Invoke((Action)(() =>
            {
                Auxiliar aux = new Auxiliar();
                HistoricoVentas hv = new HistoricoVentas();
                string jsonVentas = "";
                Historico serv = new Historico();
                serv.Url = new Juddi().getServiceUrl("Historico");
                lvHistorico.Items.Clear();
                jsonVentas = serv.devolverTodo(user.id);
                var javaScriptSerializer = new JavaScriptSerializer();
                hv = javaScriptSerializer.Deserialize<HistoricoVentas>(jsonVentas);

                for (int i = 0; i < hv.ListaVentas.Count; i++)
                {
                    lvHistorico.Items.Add(new ItemVenta { id = hv.ListaVentas[i].id, tipo = hv.ListaVentas[i].tipo, estado = hv.ListaVentas[i].estado, precio = hv.ListaVentas[i].precio});
                }
            }));
        }