private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
        {
            var fileDialog = new OpenFileDialog();
            var result     = fileDialog.ShowDialog();

            if (result != System.Windows.Forms.DialogResult.OK)
            {
                return;
            }

            var file = fileDialog.FileName;

            App.SudokuManager.GetFiles(file);
            var bindingExpression = BtnResolveAll.GetBindingExpression(IsEnabledProperty);

            if (bindingExpression != null)
            {
                bindingExpression.UpdateTarget();
            }
            var bindingExpression1 = BtnSave.GetBindingExpression(IsEnabledProperty);

            if (bindingExpression1 != null)
            {
                bindingExpression1.UpdateTarget();
            }
        }