Xamarin.iOS UICollectionView与自定义UICollectionViewSource崩溃

Question

我尝试在Xamarin.iOS中的UIControllerView中管理UICollectionView。 我尝试过很多东西，比如：https://developer.xamarin.com/guides/ios/tvos/user-interface/collection-views/或者：https://www.youtube.com/watch?v=W4H9uLjoEjM

最后，我遵循了本教程：https://forums.xamarin.com/discussion/11274/how-to-setup-uicollectionview-datasource

但我仍被封锁。我的应用程序在尝试显示带有此错误的UIViewController时崩溃：[Gotago_iOS_CollectionViewSource_ViewSourceListProgram collectionView:cellForItemAtIndexPath:]: unrecognized selector sent to instance 0x7af49db0'

这是我的代码......请帮忙吗？

public partial class ViewControllerListProgram : UIViewController
{
    private ViewSourceListProgram m_viewSource; 

        public ViewControllerListProgram(IntPtr handle)
            : base(handle)
        {
        }

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

            AppDelegate.CurrentViewController = this;

            ApiController_GetListConseilCircuit apiCtrl = new ApiController_GetListConseilCircuit();

            m_collectionView.RegisterClassForCell(typeof(CellListProgram), CellListProgram.Id);
            m_viewSource = new ViewSourceListProgram(await apiCtrl.OnlineGetListConseilCircuit());
            m_collectionView.Source = m_viewSource;
        }
    }



public class ViewSourceListProgram : UICollectionViewSource
    {
        public List<ApiController_GetListConseilCircuit.ConseilCircuit> m_lsCircuits;

    public ViewSourceListProgram(List<ApiController_GetListConseilCircuit.ConseilCircuit> lsCircuits)
    {
        m_lsCircuits = lsCircuits;
    }

    public override nint NumberOfSections(UICollectionView collectionView)
    {
        return 1;
    }

    public override nint GetItemsCount(UICollectionView collectionView, nint section)
    {
        return m_lsCircuits.Count;
    }

    public override bool ShouldHighlightItem(UICollectionView collectionView, Foundation.NSIndexPath indexPath)
    {
        return true;
    }

    public override void ItemHighlighted(UICollectionView collectionView, Foundation.NSIndexPath indexPath)
    {
        CellListProgram cell = (CellListProgram)collectionView.CellForItem(indexPath);

        Toast.MakeText("Cell highlighted", Toast.LENGTH_LONG).Show();
    }

    public override void ItemUnhighlighted(UICollectionView collectionView, Foundation.NSIndexPath indexPath)
    {
        CellListProgram cell = (CellListProgram)collectionView.CellForItem(indexPath);

        Toast.MakeText("Cell unhighlighted", Toast.LENGTH_LONG).Show();
    }

    public UICollectionViewCell GetCell(UICollectionView collectionView, NSIndexPath indexPath)
    {
        CellListProgram cell = (CellListProgram)collectionView.DequeueReusableCell(CellListProgram.Id, indexPath);

        ApiController_GetListConseilCircuit.ConseilCircuit circuitOrProgram = m_lsCircuits[indexPath.Row];

        return cell;
    }
}


public partial class CellListProgram : UICollectionViewCell
    {
        public static readonly NSString Id = new NSString("programCell");
    public CellListProgram (IntPtr handle) : base (handle)
    {
    }
}