UICollectionView in Practice

gistfile1.cs

public class ProductViewController : UICollectionViewController {
	ProductViewModel productViewModel;
	public static NSString CellId = new NSString ("product_cell");

	public ProductViewController () : base(new ProductCollectionLayout()) {		
	}

	public override void ViewDidLoad () {
		base.ViewDidLoad ();

		productViewModel = new ProductViewModel();
		CollectionView.RegisterClassForCell(typeof(ProductCell), CellId);
		CollectionView.ScrollEnabled = true;
	}

	public override void ViewDidAppear (bool animated) {
		base.ViewDidAppear(animated);
		//
		//.....Yo dawg, I herd u async, do it after the View renders...
		//
		productViewModel.GetOrderProductsAsync(ProductGroup.Id).ContinueWith((t) => {
			BeginInvokeOnMainThread(() => {
				this.CollectionView.ReloadData();
			});
		});
	}

	public override int GetItemsCount (UICollectionView collectionView, int section) {

		if(productViewModel.OrderProducts != null){
			return productViewModel.OrderProducts.Count;
		}
		return 0;
	}
	
	public override UICollectionViewCell GetCell(UICollectionView collectionView, NSIndexPath indexPath) {
		var cell = (ProductCell)collectionView.DequeueReusableCell(CellId, indexPath);
		var op = productViewModel.OrderProducts[indexPath.Row];
		cell.OrderProduct = op;
		cell.Initialize();
		return cell;
	}

	public class ProductCell : UICollectionViewCell {
		public Product Model { get; set; }
		UILabel productLabel { get; set; }

		[Export ("initWithFrame:")]
		public ProductCell(RectangleF frame)
			: base(frame) {
				//Not able to overload constructor
			}

		public void Initialize() {
			if(Model != null & Model != default(Product)) {
				//
				// ....Now ready to make use of Product model...
				//
				productLabel.Text = Model.Name;
				this.ContentView.AddSubView(ProductLabel)
			}
		}
	}
}