Grayscale image not showing inside a CoverFlowView [Xamarin Forms iOS]

Question

I am currently working with a coverflowview by using this nuget: https://github.com/AndreiMisiukevich/CardView

Works very well with the binding when I use a regular image or cachedimage (ffimageloading nuget). However now i try to grayscale the image by using a custom control. I successfully run the code to grayscale it (when propertyischanged to IsSelectable true), but for some reason the image is not showing at all, if i remove the grayscale logic, the image shows nicely.

 <cards:CoverFlowView PositionShiftValue="40"
                                         ItemsSource="{Binding Items}"
                                         VerticalOptions="FillAndExpand"
                                         HeightRequest="360">
                    <cards:CoverFlowView.ItemTemplate>
                        <DataTemplate>
                            <AbsoluteLayout HeightRequest="360">
                                 
                               <controls:GrayScaleImage Aspect="AspectFill"
                                                        AbsoluteLayout.LayoutBounds="0.0, 0.5, 1, 1"
                                                        AbsoluteLayout.LayoutFlags="All"
                                                        Source="{Binding ProgramDeserialized.Image}"
                                                        IsSelectable="{Binding IsSelectable}"/>
                           </AbsoluteLayout>
                        </DataTemplate>
                    </cards:CoverFlowView.ItemTemplate>
                </cards:CoverFlowView>

And custom control:

public class GrayScaleImage : CachedImage
{
    public static BindableProperty IsSelectableProperty = BindableProperty.Create(nameof(IsSelectable), typeof(bool), typeof(GrayScaleImage), true, propertyChanged: UpdateImage);
    
    public bool IsSelectable
    {
        get { return (bool)GetValue(IsSelectableProperty); }
        set { SetValue(IsSelectableProperty, value); }
    }
    
    private static void UpdateImage (BindableObject bindable, object oldColor, object newColor)
    {
        
        var view = (GrayScaleImage)bindable;
        if (!view.IsSelectable)
        {
            var transformations = new System.Collections.Generic.List<ITransformation>() {
                new GrayscaleTransformation()
            };
            view.Transformations = transformations;
        }
        
    }
}

Not sure what the issue might be. When i did it on a regular stacklayout bindable list, and applied the same logic, it works, so my gutfeeling is that there is some issue with the coverflowview nuget.

Answer 1

How did you set binding for the Image? I created a sample to test the function code, the grayScale image works fine.

Check the screenshot:
https://us.v-cdn.net/5019960/uploads/editor/ab/jqki5zvo7cfw.gif

Here is the code about the model class and the viewModel class, you could refer to it.

public class CustomModel
{
    public Xamarin.Forms.ImageSource MyImage { get; set; }
    public bool IsSelectable { get; set; }
}

public class CustomViewModel
{
    public ObservableCollection<CustomModel> Items { get; set; }

    public CustomViewModel()
    {
        Items = new ObservableCollection<CustomModel>();
        //add the data
    }
}