if(App.ActiveCellar == null) 
{ 
   MessageBox.Show("Aucune cave n'est ouverte."); 
   return; 
}

ObjectCollection categories = App.ActiveCellar.GetCollection((ushort)ObjectType.Category);
string VinsName = "Vins";

BaseItem ret = null;

for (int i = 0; i < categories.Count; i++)
{
	BaseItem item = (BaseItem)categories[i];
	if (item.Name.Trim() == VinsName)
	{
		ret = item;
		break;
	}
}

if (ret == null)
{
	MessageBox.Show("Catégorie \"" + VinsName + "\" introuvable.\nImpossible de continuer.");
	return;
}

ObjectCollection wines = App.ActiveCellar.GetCollection((ushort)ObjectType.Wine);

for (int i = 0; i < wines.Count; i++)
{
Wine wine = (Wine) wines[i];

	//Température
	if (wine.Category.Name.Trim() == String.Empty)
	{
		wine.Category = (Category) ret;
		wine.Save();
	}
}