protected override void OnInitialized(EventArgs e)
{
var provider = new CatalogProvider();
var types = provider.GetCatalogTypes();
types.Insert(0, new CatalogTypeModel());
Types = new ObservableCollection <CatalogTypeModel>(types);
var brands = provider.GetCatalogBrands();
brands.Insert(0, new CatalogBrandModel());
Brands = new ObservableCollection <CatalogBrandModel>(brands);
UpdateItemList();
base.OnInitialized(e);
}