private void btnNewRole_Click(object sender, RoutedEventArgs e)
        {
            FormRole form = new FormRole(context);

            form.ShowDialog();
            roleViewSource.View.Refresh();
        }
        private void btnUpdateRole_Click(object sender, RoutedEventArgs e)
        {
            var      role = roleViewSource.View.CurrentItem as role;
            FormRole form = new FormRole(role, context);

            form.ShowDialog();
            roleViewSource.View.Refresh();
        }