public override void OnNavigatedTo(NavigationParameters parameters)
 {
     base.OnNavigatedTo(parameters);
     if (parameters.ContainsKey("Tramite"))
     {
         Model = (TramitesModelo)parameters["Tramite"];
         RaisePropertyChanged(nameof(Model));
         MessagingCenter.Send <string>("Grafica", "CalcularGrafica");
     }
 }
 private async Task OnVerTramite(TramitesModelo tramite)
 {
     try
     {
         NavigationParameters parametros = new NavigationParameters();
         parametros.Add("Tramite", tramite);
         await _navigation.NavigateAsync("TramiteDetallePage", parametros);
     }
     catch (Exception ex)
     {
         await DisplayError(ex);
     }
 }