OnElementChanged method is not there to override CollectionViewRenderer in Xamarin

Question

I need to create custom control for CustomCollectionViewRenderer in Xamarin Forms as I need to show collection of images like Pinterest app in Xamarin forms. But OnElementChanged is not there to override CollectionViewRenderer. Am I doing something wrong here?

I'm using

• Xamarin.Forms NuGet Package version as 4.0.2.70
• Visual Studio Community 2019 for Mac Version 8.3.4 (build 8)
• NuGet Version: 5.3.0.6192
• Xamarin.iOS Version: 13.4.0.2 (Visual Studio Community)
• Xamarin.Android Version: 10.0.3.0 (Visual Studio Community)

    [assembly: ExportRenderer(typeof(CollectionView), typeof(CustomCollectionViewRenderer))]
    namespace MyProj.Droid
    {
        public class CustomCollectionViewRenderer : CollectionViewRenderer
        {
            public CustomCollectionViewRenderer(Context context) : base(context)
            {
            }


            protected override void OnElementChanged(ElementChangedEventArgs<ItemsView> elementChangedEvent)
                {
                    base.OnElementChanged(elementChangedEvent);

                    if (elementChangedEvent.NewElement != null)
                    {
                       StaggeredGridLayoutManager manager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.Vertical);
                        SetLayoutManager(manager);
                   }
               }
            }
        }

Answer 1

I just Did the same in my VS19 for MAC with the following configuration and everything worked

using Android.Content;
using Android.Support.V7.Widget;
using Test.Droid.PlatformRenderer;
using System.ComponentModel;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(CollectionView), typeof(CustomCollectionViewRenderer))]

namespace Test.Droid.PlatformRenderer
{
    public class CustomCollectionViewRenderer : CollectionViewRenderer
    {
        public CustomCollectionViewRenderer(Context context) : base(context)
        {
        }

        protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs changedProperty)
        {
            base.OnElementPropertyChanged(sender, changedProperty);
        }

        protected override void OnElementChanged(ElementChangedEventArgs<ItemsView> elementChangedEvent)
        {
            base.OnElementChanged(elementChangedEvent);
            if (elementChangedEvent.NewElement != null)
            {
                StaggeredGridLayoutManager manager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.Vertical);
                SetLayoutManager(manager);
            }
        }
    }
 }

VS config:

Xamarin.Forms NuGet Package version 4.5.0.356

Visual Studio Professional 2019 for Mac Version 8.3.4 (build 8)

NuGet Version: 5.3.0.6192

Xamarin.iOS Version: 13.4.0.2

Xamarin.Android Version: 10.0.3.0

So my guess is you need the latest XF!