private void ProductType_MouseDoubleClick(object sender, MouseButtonEventArgs e)
{
EditArticleTypeWindow editArticleTypeWindow = new EditArticleTypeWindow((ProductType)ProductTypeTree.SelectedItem);
editArticleTypeWindow.ShowDialog();
updateProductTree();
}
private void NewProductType_Click(object sender, RoutedEventArgs e)
{
EditArticleTypeWindow editArticleTypeWindow = new EditArticleTypeWindow(null);
editArticleTypeWindow.ShowDialog();
updateProductTree();
}