private void buttonAdd_Click(object sender, RoutedEventArgs e)
        {
            // Create a window to enter data
            var dialog = new CategoryDataWindow();

            // When data is validated
            if (dialog.ShowDialog() == true)
            {
                categoryManager.Insert(dialog.NameCategory.ToString());
                this.categoryList.Items.Refresh();
            }
        }
        private void buttonEdit_Click(object sender, RoutedEventArgs e)
        {
            // Check if a category is selected
            if (this.categoryList.SelectedItem == null)
                return;

            // Get the current category selected
            Category category = (Category)this.categoryList.SelectedItem;

            // Create a window to edit data with value
            var dialog = new CategoryDataWindow(category);

            // When data is edited
            if (dialog.ShowDialog() == true)
            {
                category.Name = dialog.NameCategory.ToString();
                categoryManager.Update(category);

                this.categoryList.Items.Refresh();
            }
        }