Жест OnFling не вызывается в ListView в формах Xamarin

Question

Я реализую жест смахивания для StackLayout (Listview внутри этого StackLayout), используя CustomRenderer в формах Xamarin. Прекрасно работает в iOS, но не работает в Android в разделе списка.

Размах работает за пределами ListView, но не работает в Listview. Я хочу, чтобы Gesture OnFling запускался при прокрутке в любом месте страницы.

Я ссылался на ссылку

https://arteksoftware.com/gesture-recognizers-with-xamarin-forms/

Вот мой код: Xaml.cs

    <?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:SwipeApp1"
             x:Class="SwipeApp1.MainPage">


    <local:FancyStackLayout BackgroundColor="Pink">
        <Grid>
            <Grid.RowSpacing>0</Grid.RowSpacing>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"></RowDefinition>
            </Grid.RowDefinitions>
            <Label Grid.Row="0" Text="Welcome to Xamarin.Forms!" 
           VerticalOptions="Center" 
           HorizontalOptions="Center"
           TextColor="Blue"/>
            <ListView x:Name="lstContatos" HasUnevenRows="True" BackgroundColor="LightSkyBlue">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <ViewCell>
                            <ViewCell.View>
                                <Grid>
                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition Width="1*"/>
                                        <ColumnDefinition Width="1*"/>
                                        <ColumnDefinition Width="2*"/>
                                        <ColumnDefinition Width="5*"/>
                                    </Grid.ColumnDefinitions>

                                    <Label Grid.Column="0" Text="{Binding userId}"></Label>
                                    <Label Grid.Column="1" Text="{Binding id}"></Label>
                                    <Label Grid.Column="2" Text="{Binding title}"></Label>
                                    <Label Grid.Column="3" Text="{Binding body}"></Label>

                                </Grid>
                            </ViewCell.View>
                        </ViewCell>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
        </Grid>
    </local:FancyLabel>


</ContentPage>

CustomRenderer.cs в проекте Droid

  using Xamarin.Forms.Platform.Android;
using Xamarin.Forms;
using SwipeApp1;
using SwipeApp1.Droid;
using Android.Views;
//[assembly: ExportRenderer(typeof(GradientStackLayout), 
typeof(GradientStackLayoutRenderer))]
[assembly: ExportRenderer (typeof(FancyStackLayout), 
typeof(FancyAndroidLabelRenderer))]

namespace SwipeApp1.Droid
{
    public class FancyAndroidLabelRenderer : 
Xamarin.Forms.Platform.Android.VisualElementRenderer<StackLayout>
    {
        private readonly FancyGestureListener _listener;
        private readonly GestureDetector _detector;

        public FancyAndroidLabelRenderer ()
        {
            _listener = new FancyGestureListener ();
            _detector = new GestureDetector (_listener);

        }

        protected override void OnElementChanged 
(ElementChangedEventArgs<StackLayout> e)
        {
            base.OnElementChanged (e);

            if (e.NewElement == null) {
                this.GenericMotion -= HandleGenericMotion;
                this.Touch -= HandleTouch;
            }

            if (e.OldElement == null) {
                this.GenericMotion += HandleGenericMotion;
                this.Touch += HandleTouch;
            }
        }

        void HandleTouch (object sender, TouchEventArgs e)
        {
            _detector.OnTouchEvent (e.Event);
        }

        void HandleGenericMotion (object sender, GenericMotionEventArgs e)
        {
            _detector.OnTouchEvent (e.Event);
        }
    }
}

GestureListner.cs

using Android.Views;
using System;

namespace SwipeApp1.Droid
{
    public class FancyGestureListener : 
GestureDetector.SimpleOnGestureListener
    {

        public override bool OnContextClick(MotionEvent e)
        {
            return base.OnContextClick(e);
        }

        public override void OnLongPress (MotionEvent e)
        {
            Console.WriteLine ("OnLongPress");
            base.OnLongPress (e);
        }

        public override bool OnDoubleTap (MotionEvent e)
        {
            Console.WriteLine ("OnDoubleTap");
            return base.OnDoubleTap (e);
        }

        public override bool OnDoubleTapEvent (MotionEvent e)
        {
            Console.WriteLine ("OnDoubleTapEvent");
            return base.OnDoubleTapEvent (e);
        }

        public override bool OnSingleTapUp (MotionEvent e)
        {
            Console.WriteLine ("OnSingleTapUp");
            return base.OnSingleTapUp (e);
        }

        public override bool OnDown (MotionEvent e)
        {
            Console.WriteLine ("OnDown");
            return base.OnDown (e);
        }

        private static int SWIPE_THRESHOLD = 100;
        private static int SWIPE_VELOCITY_THRESHOLD = 100;
        public override bool OnFling (MotionEvent e1, MotionEvent e2, float 
velocityX, float velocityY)
        {
            //Console.WriteLine ("OnFling");
            //return base.OnFling (e1, e2, velocityX, velocityY);
            bool result = false;
            try
            {
                float diffY = e2.GetY() - e1.GetY();
                float diffX = e2.GetX() - e1.GetX();
                if (Math.Abs(diffX) > Math.Abs(diffY))
                {
                    if (Math.Abs(diffX) > SWIPE_THRESHOLD && 
Math.Abs(velocityX) > SWIPE_VELOCITY_THRESHOLD)
                    {
                        if (diffX > 0)
                        {
                            onSwipeRight();
                        }
                        else
                        {
                            onSwipeLeft();
                        }
                        result = true;
                    }
                }
                else if (Math.Abs(diffY) > SWIPE_THRESHOLD && 
Math.Abs(velocityY) > SWIPE_VELOCITY_THRESHOLD)
                {
                    if (diffY > 0)
                    {
                        onSwipeBottom();
                    }
                    else
                    {
                        onSwipeTop();
                    }
                    result = true;
                }
            }
            catch (Exception exception)
            {
                //exception.printStackTrace();
            }
            return result;
        }


        public override bool OnScroll (MotionEvent e1, MotionEvent e2, float 
distanceX, float distanceY)
        {
            Console.WriteLine ("OnScroll");
            return base.OnScroll (e1, e2, distanceX, distanceY);
        }

        public override void OnShowPress (MotionEvent e)
        {
            Console.WriteLine ("OnShowPress");
            base.OnShowPress (e);
        }

        public override bool OnSingleTapConfirmed (MotionEvent e)
        {
            Console.WriteLine ("OnSingleTapConfirmed");
            return base.OnSingleTapConfirmed (e);
        }

        public void onSwipeRight()
        {
        }

        public void onSwipeLeft()
        {
        }

        public void onSwipeTop()
        {
        }

        public void onSwipeBottom()
        {
        }
    }
}

Что мне нужно сделать, чтобы получить желаемый результат?