Porting View Renderer in .net

Question

I am currently migrating my Xamarin.Forms app to .NET MAUI, and having a difficulty in migrating view renderer. In .NET MAUI I am using camera2 in my app, and using the renderer for same. My Xamarin forms code is

    public class CameraRecordV3 : View
    {
        public static readonly BindableProperty StartProperty = BindableProperty.Create(
            "Start", typeof(int), typeof(int), 6000);

        public int Start
        {
            set { SetValue(StartProperty, value); }
            get { return (int)GetValue(StartProperty); }
        }
}

    using iVue.Views;
    using System.ComponentModel;
    using Microsoft.Maui.Controls.Platform;
    using Microsoft.Maui.Controls.Handlers.Compatibility;
    
    namespace iVue.Platforms.Android.Renderers;
    
    public class CameraRecordRenderer_V3 : ViewRenderer<CameraRecordV3, CameraRecordControl_V3>
    {
        private CameraRecordControl_V3 _cameraControl;
        private DisplayTimeHelper _displayTimeHelper = new DisplayTimeHelper();
    
        public CameraRecordRenderer_V3(Context context)
          : base(context)
        {
        }
    
        protected override void OnElementChanged(ElementChangedEventArgs<CameraRecordV3> e)
        {
            base.OnElementChanged(e);
    
            if (Control == null)
            {
                _cameraControl = new CameraRecordControl_V3(Context, e.NewElement);
                SetNativeControl(_cameraControl);
            }
        }
    
     protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            var model = (CameraRecordV3)sender;
            base.OnElementPropertyChanged(sender, e);
        }
    
        protected override void Dispose(bool disposing)
        {
            base.Dispose(disposing);
            if (disposing)
            {
                _cameraControl.Dispose();
                if(Control != null)
                    Control.Dispose();
            }
        }
    }

CameraRecordControl_V3 is a viewgroup which contains a native view for android, which contains buttons and camera

    public class CameraRecordControl_V3 : ViewGroup
    {
        public CameraRecordControl_V3(Context context, CameraRecordV3 vm) : base(context)
        {
            _activity = this.Context as Activity;
            _view = _activity.LayoutInflater.Inflate(Resource.Layout.CameraRecordLayoutV2, this, false);
            AddView(_view);

            _toolbar = (Toolbar)_view.FindViewById(Resource.Id.toolbar);
            textureView = (AutoFitTextureView)_view.FindViewById(Resource.Id.textureview)
            _questionTitleView = (Button)_view.FindViewById(Resource.Id.Start);
}
}

I tried using handler in .net maui but no luck with it.

My Maui Code is as follows

public interface ICameraRecordV3 : IView 
{   
    public int StartTime { get; }
}

public partial class CameraRecordV3Handler
    {
        public static PropertyMapper<ICameraRecordV3, CameraRecordV3Handler> CustomMapper 
            = new PropertyMapper<ICameraRecordV3, CameraRecordV3Handler>(ViewHandler.ViewMapper)
        {
            [nameof(ICameraRecordV3.StartTime)] = MapStartTime,
        };

        public CameraRecordV3Handler() : base(CustomMapper)
        {

        }

        public CameraRecordV3Handler(PropertyMapper mapper = null) : base(mapper ?? CustomMapper)
        {

        }
    }



public class CameraRecordV3 : View, ICameraRecordV3 
    {
        public static readonly BindableProperty StartProperty = BindableProperty.Create(
            "StartTime", typeof(int), typeof(int), 6000);

        public int Start
        {
            set { SetValue(StartTimeProperty, value); }
            get { return (int)GetValue(StartTimeProperty); }
        }
}

//Platform Specific code

public partial class CameraRecordV3Handler : ViewHandler<ICameraRecordV3, CameraRecordControl_V3>
    {
        private CameraRecordControl_V3 _cameraControl;
        protected override CameraRecordControl_V3 CreatePlatformView()
        {
            _cameraControl = new CameraRecordControl_V3(Context, null);
            return _cameraControl;
        }

        protected override void ConnectHandler(CameraRecordControl_V3 platformView)
        {
            base.ConnectHandler(platformView);           
        }

        private static void MapStartTime(CameraRecordV3Handler handler, ICameraRecordV3 arg2)
        {
            handler.PlatformView?.UpdateStartTime(arg2.StartTime);
        }
}

//MauiProgram

builder.ConfigureMauiHandlers(handlers =>
        {
            #if __ANDROID__
            handlers.AddHandler(typeof(CameraRecordV3), typeof(iVue.Handlers.CameraRecordV3Handler));
            #endif
        });

Answer 1

You can continue to use CustomRenderer in MAUI, you just need to Remove any ExportRenderer directives as they won't be needed in .NET MAUI. And then configure each renderer using conditional compilation for each platform. You can replace handlers.AddCompatibilityRenderer with handlers.AddHandler in the documentation. Using handlers.AddCompatibilityRenderer will cause a crash.