Xamarin iOS：UICollectionView Cell的动态更新

Question

在我的xamarin ios项目中，我在UICollectionView单元格中填充图像。它能够删除或旋转图像。我想知道有什么方法可以在源更改后立即更新单元格吗？

细胞：

public class MyCellCollectionViewSource: MvxCollectionViewSource 
{
    public ObservableCollection < Animal > animals;
    ViewModel1 vm;
    public MyCellCollectionViewSource(ViewModel1 vm, int noOfImages) : base(collectionView) 
    {
        this.vm = vm;
        animals = new ObservableCollection < Animal > ();
        for (int i = 0; i < noOfImages; i++) {
            //animals.Add(i);
            switch (i) {
            case 0:
                animals.Add(new Animal() {
                    indexCell = 1,
                    image = vm.Photo1
                });
                break;
            case 1:
                animals.Add(new Animal() {
                    indexCell = 2,
                    image = vm.Photo2
                });
                break;
            case 2:
                animals.Add(new Animal() {
                    indexCell = 3,
                    image = vm.Photo3
                });
                break;
            case 3:
                animals.Add(new Animal() {
                    indexCell = 4,
                    image = vm.Photo4
                });
                break;
            case 4:
                animals.Add(new Animal() {
                    indexCell = 5,
                    image = vm.Photo5
                });
                break;
            case 5:
                animals.Add(new Animal() {
                    indexCell = 1,
                    image = newPostDetailViewModel.Photo1
                });
                break;
            }

        }
        public override UICollectionViewCell GetCell(UICollectionView collectionView, NSIndexPath indexPath) 
        {
            var cell = (MyCell) collectionView.DequeueReusableCell(animalCellId, indexPath);
            Cell.PopulateCell(indexPath.Row);
            cell.Closebtn.TouchUpInside += delegate {
                MyCellCollectionViewSource source = collectionView.DataSource as MyCellCollectionViewSource;
                vm.DeleteCommand.Execute(indexPath.Row);
                ReloadData();
            };

            cell.UserPostbtn.TouchUpInside += delegate {
                MyCellCollectionViewSource source = collectioview.DataSource as MyCellCollectionViewSource;
                newPostDetailViewModel.EditPhotoCommand.Execute(indexPath.Row);
                ReloadData();
            };
        }

    }

单元格具有CloseBtn和UserPostBtn。

当我点击CloseBtn时，我可以在我的observableCollection＆＃39;动物＆＃39;该单元格被删除。但是我看不到它们反映在我的馆藏视图上，如果我再回来重新加载整个页面，那么我可以看到我的变化。

同样，如果我点击UserPostBtn，它会旋转图像，但那些更改不会动态反映，我必须返回并重新加载重新加载整个页面以更新单元格。