Qfyilyi

I have upgraded from Xamarin Forms 2.5 to 3.4 and I started getting a FAB button issue on Android only. The button appears right for the first time, but when I push and pop few times (on top of the page containing the button), the button suddenly shrinks around 40%

Here is my renderer code:

using Xamarin.Forms;



namespace MyApp.SLayout

{

    [Preserve(AllMembers = true)]

    public class SFloatingActionButton : Button

    {

        public static BindableProperty ButtonColorProperty = BindableProperty.Create(nameof(ButtonColor), typeof(Color),

            typeof(SFloatingActionButton), Color.Accent);



        public Color ButtonColor

        {

            get => (Color) GetValue(ButtonColorProperty);

            set => SetValue(ButtonColorProperty, value);

        }

    }

}



using System;

using Android.Content;

using Android.Content.Res;

using Android.Graphics;

using Android.Runtime;

using Android.Support.V4.View;

using FFImageLoading;

using MyApp.Droid.SLayout;

using MyApp.SLayout;

using Xamarin.Forms;

using Xamarin.Forms.Platform.Android;

using FAB = Android.Support.Design.Widget.FloatingActionButton;



[assembly: ExportRenderer(typeof(SFloatingActionButton), typeof(FloatingActionButtonRenderer))]

namespace MyApp.Droid.SLayout

{

    [Preserve(AllMembers = true)]

    public class FloatingActionButtonRenderer : Xamarin.Forms.Platform.Android.AppCompat.ViewRenderer<SFloatingActionButton, FAB>

    {

        private readonly Context _context;

        private FAB _fab;

        private Bitmap _img;



        public FloatingActionButtonRenderer(Context context) : base(context)

        {

            _context = context;

        }



        protected override void OnElementChanged(ElementChangedEventArgs<SFloatingActionButton> e)

        {

            base.OnElementChanged(e);

            if (Control == null)

            {

                // Instantiate the native control

                _fab = new FAB(_context);

                ViewCompat.SetBackgroundTintList(_fab, ColorStateList.ValueOf(Element.ButtonColor.ToAndroid()));

                _fab.UseCompatPadding = true;

                string imageFile = Element.Image.File;

                string drawableNameWithoutExtension = System.IO.Path.GetFileNameWithoutExtension(imageFile)?.ToLower();

                int imageResourceName = _context.Resources.GetIdentifier(drawableNameWithoutExtension, "drawable", _context.PackageName);

                _img = BitmapFactory.DecodeResource(_context.Resources, imageResourceName);

                _fab.SetImageBitmap(_img);

                SetNativeControl(_fab);

            }



            if (e.OldElement != null)

            {

                _img?.TryDispose();

                _fab.Click -= Fab_Click;

            }



            if (e.NewElement != null)

            {

                _fab.Click += Fab_Click;

            }

        }





        protected override void OnLayout(bool changed, int l, int t, int r, int b)

        {

            base.OnLayout(changed, l, t, r, b);

            Control.BringToFront();

        }



        private void Fab_Click(object sender, EventArgs e)

        {

            // proxy the click to the element

            ((IButtonController) Element).SendClicked();

        }

    }

}

Xamarin.Forms 2.5 is a very old version, with many changes since 3.0.Here is a demo that you can refer.(This should be a comment, but my reputation is less than 50).