UPDATE :

So i am not sure if this is a bug or not but I have raised one in Github anyway, which can be tracked here: https://github.com/dotnet/maui/issues/9720

QUESTION :

So I have been trying out MAUI extensively lately and was trying to Create a Custom Control I guess and I ran into this weird problem, the CreatePlatform method was never getting called, at first I thought this was because I was using a MAUI class library and there was some issue with them, So instead I created another control in the same MAUI project instead of doing it through a CL and to my surprise even then it did not work.

My code is as follows:

Interface:

public interface IExtendedLabel : ILabel
{
    bool HasUnderline { get; }
    Color UnderlineColor { get; }
}

Label class:

public class ExtendedLabel : Label, IExtendedLabel
{
    public readonly BindableProperty HasUnderlineProperty = BindableProperty.Create(
        nameof(HasUnderline),
        typeof(bool),
        typeof(ExtendedLabel),
        true);

    public bool HasUnderline
    {
        get => (bool)GetValue(HasUnderlineProperty);
        set => SetValue(HasUnderlineProperty, value);
    }

    public readonly BindableProperty UnderlineColorProperty = BindableProperty.Create(
       nameof(UnderlineColor),
       typeof(Color),
       typeof(ExtendedLabel),
       Colors.Black);

    public Color UnderlineColor
    {
        get => (Color)GetValue(HasUnderlineProperty);
        set => SetValue(HasUnderlineProperty, value);
    }
}

My shared handler:

using System;
using MAUI.FreakyControls;
using Microsoft.Maui.Handlers;
#if ANDROID
using NativeView = AndroidX.AppCompat.Widget.AppCompatTextView;
#endif
#if IOS
using NativeView = UIKit.UILabel;
#endif
namespace Samples
{
    public partial class ExtendedLabelHandler : ViewHandler<IExtendedLabel,NativeView>
    {
        #region ctor 

        public static CommandMapper<IExtendedLabel, ExtendedLabelHandler> CommandMapper = new(ViewCommandMapper);


        public ExtendedLabelHandler() : base(FreakyEditorMapper)
        {

        }

        public ExtendedLabelHandler(IPropertyMapper mapper = null) : base(mapper ?? FreakyEditorMapper)
        {

        }

        #endregion

        #region Mappers

        public static IPropertyMapper<IExtendedLabel, ExtendedLabelHandler> FreakyEditorMapper = new PropertyMapper<IExtendedLabel, ExtendedLabelHandler>(ViewMapper)
        {
            [nameof(IExtendedLabel.HasUnderline)] = MapHasUnderlineWithColor,
            [nameof(IExtendedLabel.UnderlineColor)] = MapHasUnderlineWithColor
        };

        public static void MapHasUnderlineWithColor(ExtendedLabelHandler handler, IExtendedLabel entry)
        {

        }

        #endregion
    }
}

Handler Android:

public partial class ExtendedLabelHandler
    {
        protected override AppCompatTextView CreatePlatformView()
        {
            var nativeView = new AppCompatTextView(this.Context)
            {

            };
            return nativeView;
        }

        private void HandleNativeHasUnderline(bool hasUnderline, Color underlineColor)
        {
            if (hasUnderline)
            {
                var AndroidColor = underlineColor.ToNativeColor();
                var colorFilter = BlendModeColorFilterCompat.CreateBlendModeColorFilterCompat(
                    AndroidColor, BlendModeCompat.SrcIn);
                PlatformView.Background?.SetColorFilter(colorFilter);
            }
            else
            {
                PlatformView.Background?.ClearColorFilter();
            }
        }
    } 

My iOS handler:

public partial class ExtendedLabelHandler
    {
        CoreAnimation.CALayer bottomLine;

        protected override UILabel CreatePlatformView()
        {
            return new UILabel();
        }

        private void HandleNativeHasUnderline(bool hasUnderline, Color underlineColor)
        {
            if (hasUnderline)
            {
                var uiColor = underlineColor.ToNativeColor();
                bottomLine = BottomLineDrawer(uiColor);
                bottomLine.Frame = new CGRect(x: 0, y: PlatformView.Frame.Size.Height - 5,
                    width: PlatformView.Frame.Size.Width, height: 1);
                PlatformView.Layer.AddSublayer(bottomLine);
                PlatformView.Layer.MasksToBounds = true;
            }
            else
            {
                bottomLine?.RemoveFromSuperLayer();
            }
        }
    }

Adding the handler:

 handlers.AddHandler(typeof(IExtendedLabel), typeof(ExtendedLabelHandler));

Am I doing something wrong?

You can find the full code on my repo here which has a full working example of the method never getting called for some reason: https://github.com/FreakyAli/MAUI.FreakyControls/tree/r1-gh/feat/freakyeditor

CodePudding user response：

So the issue was my registration, I was registering my interface instead of the class of my custom control:

 handlers.AddHandler(typeof(ExtendedLabel), typeof(ExtendedLabelHandler));

Goodluck to anyone looking for this.