WPF RichTextBox and specific culture issues

Question

Im trying to set Language for System.Windows.Control.RichTextBox as "es-PE", but I found
some issues, for example in some computers, works perfectly and SpellChecker is enabled
with "es-PE" language, but in others it just works with "en-US", so I Dont know whats the matter with
that control, I was using the following code in XAML and C# :

this is code when users select row from GridView and then shows the screenshot attached

 private void dlstInformes_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            if (!dlstInformes.SelectedItem.ToString().Equals(""))
            {
                var source_ = dlstInformes.SelectedItems;
                InformeMedico demo = new InformeMedico(); //New Window

                foreach (informeMedico item in source_)
                {
                    numeroinforme = item.numeroinforme.ToString();
                    nombreinforme = item.nombreinforme;
                    fechainforme = item.fechainforme.ToString();
                    nombreMedico = item.medicoCompleto.ToString();
                    turnoMedico = item.turno.ToString();
                    nombrePaciente = item.pacienteCompleto.ToString();
                    nombreExamen = item.nombreinforme.ToString();

                }
                demo.Language = XmlLanguage.GetLanguage("es-PE");
                demo.txtNombreExamen.Text = nombreinforme;
                demo.lblNroInforme.Content = numeroinforme;
                demo.lblMedicoNombre.Content = nombreMedico;
                demo.lblNombrePac.Content = nombrePaciente;
                demo.lblTurnoMedico.Content = turnoMedico;
            using (DB db = new DB())
            {
                var lstTM = (from ea in db.EXAMENXATENCIONs where ea.turnomedico.Trim() != " " select ea.turnomedico).Distinct().ToList();
                string tm = (from ea in db.EXAMENXATENCIONs where ea.codigo == Convert.ToInt32(numeroinforme) select ea.turnomedico).FirstOrDefault();
                demo.cboTurnoMed.ItemsSource = lstTM;
                demo.cboTurnoMed.SelectedItem = tm;
                demo.cboTurnoMed.SelectedValue = tm;
                demo.cboTurnoMed.Text = tm;
                if (tm.Equals("RE/ES") || tm.Equals("RE/HS") || tm.Equals("RE/HT") || tm.Equals("RE/KV") || tm.Equals("HH/CS") || tm.Equals("HH/ES") || tm.Equals("HH/HS") || tm.Equals("HH/HT") || tm.Equals("HH/KV"))
                {
                    demo.FirmaUnoDefault.Content = "DEN51";
                    demo.FirmaDosDefault.Content = tm;
                }
                else if (tm.Equals("HH/AO") || tm.Equals("IU/AO") || tm.Equals("RE/AO") || tm.Equals("HH/JA") || tm.Equals("RR/JA") || tm.Equals("IU/JA"))
                {
                    demo.FirmaUnoDefault.Content = "DEN51";
                    demo.FirmaDosDefault.Content = "AOY20";
                }
                else if (tm.Equals("IU/CS") || tm.Equals("IU/ES") || tm.Equals("IU/HT") || tm.Equals("IU/KV"))
                {
                    demo.FirmaUnoDefault.Content = "IUU17";
                    demo.FirmaDosDefault.Content = tm;
                }
                else if (tm.Equals("RD/DE"))
                {
                    demo.FirmaUnoDefault.Content = "REE";
                    demo.FirmaDosDefault.Content = "DEN51";
                }
                else if (tm.Equals("RE/JC"))
                {
                    demo.FirmaUnoDefault.Content = "REE";
                    demo.FirmaDosDefault.Content = "JCCH25";
                }
                else if (tm.Equals("RE/CS"))
                {
                    demo.FirmaUnoDefault.Content = "DEN51";
                    demo.FirmaDosDefault.Content = "REE";
                }
            }
            demo.lblCodigoClase.Visibility = Visibility.Hidden;
            demo.lblCodigoEstudio.Visibility = Visibility.Hidden;
            demo.lblCodigoPaciente.Visibility = Visibility.Hidden;
            demo.FirmaUnoDefault.Visibility = Visibility.Hidden;
            demo.FirmaDosDefault.Visibility = Visibility.Hidden;
            demo.rtbHallazgo.Language = XmlLanguage.GetLanguage("es-PE");
            demo.rtbConclusion.Language = XmlLanguage.GetLanguage("es-PE");
            demo.rtbTecnica.Language = XmlLanguage.GetLanguage("es-PE");

            demo.rtbHallazgo.SpellCheck.IsEnabled = true;
            demo.rtbTecnica.SpellCheck.IsEnabled = true;
            demo.rtbConclusion.SpellCheck.IsEnabled = true;
            demo.rtbConclusion.SpellCheck.SpellingReform = SpellingReform.PreAndPostreform;

            demo.ResizeMode = ResizeMode.NoResize;

            demo.Closing += new System.ComponentModel.CancelEventHandler(notClosing_CancelEventArgs);

            demo.ShowDialog();
        }
        else
        {
            MessageBox.Show("Seleccione un item", "Error", MessageBoxButton.OK, MessageBoxImage.Asterisk);
        }
    }

I also trying configurate and removing "en-US" language from SO, when it happens spellchecker stop completly and when I Re-Add that language for keyboard, it SpellChecker reappears.

Stills not working with "es-PE" or just Spanish as Parent

Thanks in Advance!

Answer 1

I'm not sure if this will help, but it might be worth a shot.

In the Application.StartUp event add the following code

FrameworkElement.LanguageProperty.OverrideMetadata(
            typeof(FrameworkElement),
            new FrameworkPropertyMetadata(
                XmlLanguage.GetLanguage(
                CultureInfo.CurrentCulture.IetfLanguageTag)));

Or you can modify it to specify es-PE instead of the current culture.

This post might provide more in-depth details: Getting a WPF application to pick up the correct regional settings