当在xamarin中滚动CollectionView图片时，该怎么办？

<CollectionView ItemsSource="{Binding ImageList}">
    <CollectionView.ItemTemplate>
        <DataTemplate>
            <Image Source="{Binding ImageUrl}" />
        </DataTemplate>
    </CollectionView.ItemTemplate>
</CollectionView>

public class MyViewModel : INotifyPropertyChanged
{
    public ObservableCollection<MyImageModel> ImageList { get; set; }

    public MyViewModel()
    {
        ImageList = new ObservableCollection<MyImageModel>();
        // 添加图片数据到ImageList
    }
}

public partial class MyPage : ContentPage
{
    public MyPage()
    {
        InitializeComponent();
        BindingContext = new MyViewModel();
    }
}